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## PHOSGENE 9

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## CAS No. 75-44-5 11

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## ACUTE EXPOSURE GUIDELINE LEVELS 20

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## Draft-Revised 22

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31PHOSGENE DRAFT REVISED 1: 10/2009 Page 2 of 73

PREFACE 1

2 Under the authority of the Federal Adviso ry Committee Act (FACA) P. L. 92-463 of 3 1972, the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous 4 Substances (NAC/AEGL Committee) has been es tablished to identify, review and interpret 5 relevant toxicologic and other scientific data and develop AEGLs for high priority, acutely toxic 6
chemicals. 7

8 AEGLs represent threshold exposure limits for the general public and are applicable to 9 emergency exposure periods ranging from 10 minutes to 8 hours. Three levels C AEGL-1, 10

AEGL-2 and AEGL-3 C are developed for each of five exposure periods (10 and 30 minutes, 1 11 hour, 4 hours, and 8 hours) and are distinguished by va rying degrees of severity of toxic effects. 12
The three AEGLs are defined as follows: 13

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AEGL-1 is the airborne concentration (expressed as parts per million or milligrams per 15 cubic meter [ppm or mg/m3]) of a substance above which it is predicted that the general 16 population, including susceptible individuals, could experience notable discomfort, 17 irritation, or certain asymptomatic, non-sensor y effects. However, the effects are not 18 disabling and are transient and reversible upon cessation of exposure. 19

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AEGL-2 is the airborne concentration (expressed as ppm or mg/m3) of a substance 21 above which it is predicted that the general population, including susceptible 22 individuals, could experience irreversible or other serious, long-lasting adverse health 23 effects or an impaired ability to escape. 24

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AEGL-3 is the airborne concentration (expressed as ppm or mg/m3) of a substance 26 above which it is predicted that the general population, including susceptible 27 individuals, could experience life-threatening health effects or death. 28

29 Airborne concentrations below the AEGL-1 represent exposure levels that could 30 produce mild and progressively increasing but transient and nondisabling odor, taste, and 31 sensory irritation or certain asymptomatic, non- sensory effects. With increasing airborne 32 concentrations above each AEGL, there is a progressive increase in the likelihood of occurrence 33 and the severity of effects described for each corresponding AEGL. Although the AEGL values 34 represent threshold levels for the general public, including susceptible subpopulations, such as 35 infants, children, the elderly, persons with asthma, and those with other illnesses, it is 36 recognized that individuals, subject to unique or idiosyncratic responses, could experience the 37 effects described at concentrations below the corresponding AEGL. 38PHOSGENE DRAFT REVISED 1: 10/2009 Page 3 of 73

EXECUTIVE SUMMARY 1

2 Phosgene is a colorless gas at ambient temperature and pressure. Its odor has been 3 described as similar to new-mown hay. Phosgene is manufactured from a reaction of carbon 4 monoxide and chlorine gas in the presence of activated charcoal. The production of dyestuffs, 5 isocyanates, carbonic acid esters (polycarbonates), acid chlorides, insecticides, and 6 pharmaceutical chemicals requires phosgene. Manufacture of phosgene is approximately 1 7 million tons per year in the United States with more than 10,000 workers involved in its 8 manufacture and use. Manufacture of phosgene in the United States is almost entirely captive, 9 in that it is used in the manufacture of other chemicals within a plant boundary. 10

11 Inhalation is the most important route of exposure for phosgene. Because of its mild 12 upper respiratory, eye and skin irritancy, and a mildly pleasant odor, an exposed victim may not 13 actively seek an avenue of escape before lower respiratory damage has occurred (Currie et al., 14 1987a; Lipsett et al., 1994). Pulmonary edema is the cause of death after a clinical latent period 15

of  24 hours (Franch and Hatch, 1986). 16

17 Appropriate data were not available for de riving AEGL-1 values for phosgene. Odor 18 cannot be used as a warning for potential exposure. The odor threshold is reported to be 19 between 0.5 to 1.5 ppm, a value above or approaching AEGL-2 and AEGL-3 values, and 20 tolerance to the pleasant odor of phosgene occurs rapidly. Furthermore, following odor 21 detection and minor irritation, serious effects may occur after a clinical latency period of  24 22
hours. 23

24 The NOAEL for increased PMNs in BAL fluid observed in dogs (2.3 ppm for 30 25 minutes) (Pauluhn, 2006c) was used as the basis for deriving AEGL-2 values. The dog was 26 chosen over rodents because, with regard physiology of the respiratory tract and acinar structure 27 of the lung, dogs are more similar to humans than rodents. This endpoint was chosen because 28 BAL fluid changes are a sensitive marker of phosgene-induced noncardiogenic pulmonary high29 permeability edema following acute inhalation exposure (Pauluhn et al., 2007). 30

31 An uncertainty factor of 1 was applied for interspecies extrapolation. In rats, c x t 32 products of between 48 ppm·min and 60 ppm·min induced increased protein in BAL fluid , and 33 no increase was noted from 24-30 ppm·min. In mice and hamsters, a c x t product of 48 34 ppm·min induced an increase of protein in BAL fluid, and no increase was noted at 24 ppm·min. 35 However, in dogs, a c x t product of 129 ppm·min was necessary to cause an increase in protein 36 in BAL fluid, and no increase was observed at 63 ppm·min. Thus, the CT product required to 37 induce an increase in protein in BAL fluid in dogs is approximately two-fold greater than in 38 rodents, and the NOAEL for increased BAL protein in dogs (63 ppm·min) is higher than the 39 LOAEL values in rodents (48-60 ppm·min). Additionally, with regard to physiology of the 40 respiratory tract and acinar structure of the lung, dogs are more similar to humans than rodents 41 (Pauluhn, 2006a, 2006b, 2006c; Pauluhn et al., 2007). Collectively, these data suggest that an 42 interspecies uncertainty factor of no more than 1 is justified when extrapolating from laboratory 43
animals to humans. 44

45PHOSGENE DRAFT REVISED 1: 10/2009 Page 4 of 73

An uncertainty factor of 3 was applied to account for sensitive human subpopulations. 1 The intraspecies UF of 3 is considered sufficient due to the steep concentration-response curve 2 (death in 2/10 rats exposed to 52.3 ppm and 6/10 exposed to 61.9 ppm for 10 min; 4/10 exposed 3 to 13.4 ppm and 10/10 exposed to 16.7 ppm for 30-min; 4/10 exposed to 7.4 ppm and 10/10 4 exposed to 11.8 ppm for 1-hr; Pauluhn, 2006a) which implies limited intra-individual 5 variability. Also, the mechanism of phosgene toxicity (binding to macromolecules and 6 irritation) is not expected to vary greatly between individuals. The concentration-time 7 relationship for many irritant and systemically-acting vapors and gases may be described by c n 8 x t = k, where the exponent, n, ranges from 0.8 to 3.5 (ten Berge et al., 1986). Haber = s Law c x 9 t = k; n=1 has been shown to be valid for phosgene within certain limits and will be used for 10 scaling of the AEGL values for phosgene. 11

12 The AEGL-3 values were based on an estimated 1-hour lethality threshold of 3.9 ppm 13 (BMCL 05 ) in rats (Pauluhn, 2006a). Uncertainty factor application and time scaling are as 14
described above for derivation of AEGL-2 values. 15

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The calculated values are listed in the table below. 17

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TABLE S 1. Summary of Proposed AEGL Values for Phosgene

Classification 10-min 30-min 1-hr 4-hr 8-hr Endpoint (Reference)

AEGL-1 (Nondisabling) NR NR NR NR NR Not Recommended

AEGL-2 (Disabling) 2.3 ppm (9.5 mg/m 3 ) 0.77 ppm (3.2 mg/m 3 ) 0.38 ppm (1.6 mg/m 3 ) 0.096 ppm (0.39 mg/m 3 ) 0.048 ppm (0.19 mg/m 3 ) Increased PMNs in BAL fluid in dogs (Pauluhn, 2006c)

AEGL-3 (Lethal) 7.8 ppm (32 mg/m 3 ) 2.6 ppm (11 mg/m 3 ) 1.3 ppm (5.3 mg/m 3 ) 0.33 ppm (1.4 mg/m 3 ) 0.16 ppm (0.66 mg/m 3 ) Estimated 1-hr lethality threshold (BMCL 05 ) in rats (Pauluhn, 2006a)

NR: Not Recommended. Absence of AEGL-1 values does not imply that exposure to concentrations below AEGL-2
are without effect. 19PHOSGENE DRAFT REVISED 1: 10/2009 Page 5 of 73

TABLE OF CONTENTS 1

PREFACE........................................................................................................................ ........................... 2 2

EXECUTIVE SUMMARY.............................................................................................................. ........... 3 3

LIST OF TABLES................................................................................................................. ..................... 8 4

1. INTRODUCTION................................................................................................................ .............. 9 5

2. HUMAN TOXI CITY DATA......................................................................................................... .. 10 6

2.1. Acute Lethality ........................................................................................................... ............. 10 7

2.2. Nonlethal Toxicity........................................................................................................ ........... 11 8 2.2.1. Case Reports............................................................................................................ ............ 12 9 2.2.2. Epidemiologic Studies ................................................................................................... ..... 14 10

2.3. Developmental/Reproductive Toxicity.................................................................................... 15 11

2.4. Genotoxicity .............................................................................................................. .............. 15 12

2.5. Carcinogenicity........................................................................................................... ............. 15 13

2.6. Summary................................................................................................................... ............... 15 14

3. ANIMAL TOXI CITY DATA........................................................................................................ .. 16 15

3.1. Acute Lethality ........................................................................................................... ............. 16 16

3.1.1. Mouse................................................................................................................... ............... 16 17

3.1.2. Rats.................................................................................................................... .................. 16 18 3.1.3. Guinea Pigs ............................................................................................................. ............ 19 19

3.1.4. Rabbits................................................................................................................. ................ 20 20

3.1.5. Cats.................................................................................................................... .................. 20 21 3.1.6. Dogs .................................................................................................................... ................ 20 22

3.1.7. Goats ................................................................................................................... ................ 21 23 3.1.8. Sheep................................................................................................................... ................ 21 24

3.1.9. Non-human Primates..................................................................................................... ..... 21 25

3.2. Nonlethal Toxicity........................................................................................................ ........... 22 26

3.2.1. Mice.................................................................................................................... ................. 22 27

3.2.2. Rats.................................................................................................................... .................. 23 28 3.2.3. Guinea Pigs ............................................................................................................. ............ 30 29

3.2.4. Hamsters................................................................................................................ .............. 30 30

3.2.5. Rabbits................................................................................................................. ................ 31 31 3.2.6. Dogs .................................................................................................................... ................ 31 32 3.2.7. Sheep................................................................................................................... ................ 32 33

3.2.8. Goats ................................................................................................................... ................ 33 34

3.2.9. Cats.................................................................................................................... .................. 33 35 3.2.10. Monkeys ............................................................................................................... ......... 33 36PHOSGENE DRAFT REVISED 1: 10/2009 Page 6 of 73

3.3. Repeated Exposure Studies ................................................................................................. .... 33 1

3.4. Developmental/Reproductive Toxicity.................................................................................... 35 2

3.5. Genotoxicity .............................................................................................................. .............. 35 3

3.6. Carcinogenicity........................................................................................................... ............. 35 4

3.7. Summary................................................................................................................... ............... 35 5

4. SPECIAL CONS IDERATIONS ...................................................................................................... 39 6

4.1. Metabolism and Disposition................................................................................................ .... 39 7

4.2. Mechanism of Toxicity..................................................................................................... ....... 39 8

4.3. Structure-Activity Relationships .......................................................................................... ... 39 9

4.4. Other Relevant Information................................................................................................ ..... 40 10

4.4.1. Haber = s Law and Time-Scaling.......................................................................................... 40 11 4.4.2. Species Variability ..................................................................................................... ......... 41 12

5. RATIONALE AND PROP OSED AEGL-1 ..................................................................................... 42 13

5.1. Human Data Relevant to AEGL-1........................................................................................... 42 14

5.2. Animal Data Relevant to AEGL-1 .......................................................................................... 42 15

5.3. Derivation of AEGL-1...................................................................................................... ....... 42 16

6. RATIONALE AND PROP OSED AEGL-2 ..................................................................................... 43 17

6.1. Human Data Relevant to AEGL-2........................................................................................... 43 18

6.2. Animal Data Relevant to AEGL-2 .......................................................................................... 43 19

6.3. Derivation of AEGL-2...................................................................................................... ....... 43 20

7. RATIONALE AND PROP OSED AEGL-3 ..................................................................................... 44 21

7.1. Human Data Relevant to AEGL-3........................................................................................... 44 22

7.2. Animal Data Relevant to AEGL-3 .......................................................................................... 44 23

7.3. Derivation of AEGL-3...................................................................................................... ....... 44 24

8. SUMMARY OF PROPOSED AEGLS............................................................................................ 46 25

8.1. AEGL Values and Toxicity Endpoints.................................................................................... 46 26

8.2. Comparison with Other Standards and Guidelines.................................................................. 46 27

8.3 Data Adequacy and Research Needs ...................................................................................... 47 28

9. REFERENCES.................................................................................................................. ............... 47 29PHOSGENE DRAFT REVISED 1: 10/2009 Page 7 of 73

APPENDIX A: DERIVATION OF AEGL VALUES.............................................................................. 56 1

APPENDIX B: DERIVATION SUMMARY FOR PHOSGENE AEGLS............................................... 59 2

APPENDIX C: CATEGORY PLOT FOR PHOSGENE.......................................................................... 63 3

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LIST OF TABLES 1

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TABLE S 1. Summary of Proposed AEGL Values fo r Phosge ne ...................................................................4 3
TABLE 1. Physical and Chemical Data ..................................................................................10 4 TABLE 2. Acute Irritative Effects of Phosgene Exposure in Humans .................................11 5 TABLE 3. Effect of Phosgene Exposure in Humans ..............................................................12 6 TABLE 4. Acute Lethality of Phosgene in Mice .....................................................................16 7 TABLE 5. Acute Lethality Data in Rats Exposed to Phosgene .............................................18 8 TABLE 6. Acute Lethality of Phosgene in Rats .....................................................................19 9 TABLE 7. Acute Lethality of Phosgene in Guinea Pigs .........................................................20 10 TABLE 8. Acute Lethality of Phosgene in Rabbits ................................................................20 11 TABLE 9. Acute Lethality of Phosgene in Dogs ....................................................................21 12 TABLE 10. Group Means (±SD) of Findings in Rats Exposed for 4 Hours to Phosgene ...24 13 TABLE 11. Group Means (±Sd) of Findings In Rats Exposed for 30 Minutes to Phosgene 14

............................................................................................................................... .......................25 15 TABLE 12. Summary of Non-Lethal Animal Inhalation Studies With Phosgene ..............37 16 TABLE 13. Mean BAL Protein Values for Various Species..................................................42 17 TABLE 14. AEGL-1 Values for Phosgene ...............................................................................43 18 TABLE 15. AEGL-2 Values for Phosgene ...............................................................................44 19 TABLE 16. AEGL-3 Values for Phosgene ...............................................................................45 20 TABLE 17. Summary of AEGL Values for Phosgene ............................................................46 21 TABLE 18. Extant Standards and Guidelines for Phosgene .................................................46 22 23PHOSGENE DRAFT REVISED 1: 10/2009 Page 9 of 73

1. INTRODUCTION 1

2 Phosgene is a colorless gas at ambient temperature and pressure. Its odor has been 3 described as similar to new-mown hay (Leonardos et al., 1968). This mild odor and the weak 4 acute irritant properties, however, provide little warning of its presence (Lipsett et al., 1994). 5 The odor threshold has been established between 0.5 to 1.5 ppm (2.06 to 6.18 mg/m 3 ) (Lipsett 6 et al., 1994). 7

8 Phosgene is manufactured from a reaction of carbon monoxide and chlorine gas in the 9 presence of activated charcoal. Manufacture of phosgene is approximately 1 million tons per 10 year in the United States with more than 10,000 workers involved in its manufacture and use 11 (Currie et al., 1987a). Manufacture of phosgene in the United States is almost entirely captive, 12 in that >99% is used in the manufacture of other chemicals within a plant boundary. Only one 13 company sells phosgene on the U.S. merchant market. Over 80% of the phosgene used in the 14
United States is involved in the manufacture of polyisocyanates in the polyurethane industry. 15 The polycarbonate industry accounts for approximately 10% of phosgene used, and the 16 remaining 10% is utilized in the production of aliphatic diisocyanates, monoisocyanates, 17 chloroformates, agrochemicals, and intermediates for dyestuffs and pharmaceuticals. Phosgene 18 can also be used in metal recovery operations (platinum, uranium, plutonium, and niobium), and 19 has been used for manufacturing aluminum chloride, beryllium chloride, and boron trichloride. 20 It has been patented as a stabilizer for liquid SO 2 . Additionally, many pesticides have been 21 produced by reaction of a thiol or dithiol with phosgene to produce thiol chloroformates. (Kirk22 Othmer, 1991). 23

24 Inhalation is the most important route of exposure for phosgene. Because of its mild 25 upper respiratory, eye and skin irritancy, and a mildly pleasant odor, an exposed victim may not 26 actively seek an avenue of escape before lower respiratory damage has occurred (Currie et al., 27 1987a; Lipsett et al., 1994). Pulmonary edema is the cause of death after a clinical latent period 28

of  24 hours (Franch and Hatch, 1986). 29

30 The chemical structure is depicted below, and the physicochemical properties of 31 phosgene are presented in Table 1. 32

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TABLE 1. Physical and Chemical Data

Parameter Data Reference
Synonyms Carbonyl chloride, Carbon oxychloride, Carbonic dichloride, Chloroformyl chloride Lipsett et al., 1994; U.S. EPA, 1986

Chemical Formula COCL 2 Lipsett et al., 1994 Molecular Weight 98.92 Lipsett et al., 1994 CAS Registry No. 75-44-5 Lipsett et al., 1994 Physical State Gas Lipsett et al., 1994 Vapor Pressure 1215 mm Hg at 20  C U.S. EPA, 1986 Vapor Density 3.4 (air = 1) Lipsett et al., 1994 Specific Gravity 1.381 g/l at 20  C ACGIH, 2000 Melting/Boiling/Flash Point -128  C/8.2  C/not applicable Lipsett et al., 1994/NIOSH, 2005 Solubility Decomposes in water and alcohol; soluble in organic solvents U.S. EPA, 1986

Conversion factors in air 1 ppm = 4.11 mg/m 3
1 mg/m 3 = 0.24 ppm Lipsett et al., 1994

Incompatibility Alkalis, ammonia, alcohols, copper NIOSH, 2005

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2. HUMAN TOXICITY DATA 3 2.1. Acute Lethality 4

5 Based on observations during World War I, the two minute LC 50 value for humans was 6 estimated to be 790 ppm (Chasis, 1944). 7

8 Many case reports describe symptomology and post-mortem results from human 9 phosgene poisonings; however, exposure concentr ations were not reported. Six men were 10 occupationally exposed to phosgene when a pipe ruptured (Stavrakis, 1971). A 24-year-old 11 who had received the heaviest exposure arrived at the emergency room minutes after the 12 accident. Upon admission, the patient was symptom-free; however, he was treated with 13 methenamine intravenously and admitted for a 24-hour observation. During this time, he 14 remained symptom free and was discharged with no evidence of phosgene injury. The other 15 five patients arrived at the emergency room between 6 and 12 hours after the accident, present16 ing with various degrees of phosgene intoxication. One 31-year-old who had been exposed A in 17 almost the same degree as the previous patient @ rapidly developed pulmonary edema. He also 18 exhibited extreme hemoconcentration and leukocytosis. He did not respond to methenamine 19 treatment and died 3.5 hours after admission. The other four exposed workers were 20 hospitalized for various periods of time and recovered satisfactorily. 21

22 A 23-year-old man (healthy nonsmoker) was exposed to at least 5-10 ppm phosgene 23 (estimated concentration) for five to ten seconds (Bradley and Unger, 1982). He began 24 coughing upon exposure to phosgene and experienced dyspnea and chest tightness within thirty 25 minutes. Four hours after exposure, he was hospitalized with hypotension, tachycardia, 26 tachypnea, cyanosis, and pulmonary edema. The patient was intubated and administered 27 dopamine and methylprednisolone. From the s econd to the sixth day of hospitalization, he 28 developed mediastinal and subcutaneous emphysema, bilateral pneumohydrothoraces, elevated 29PHOSGENE DRAFT REVISED 1: 10/2009 Page 11 of 73

white blood cell counts, fever, and hemiparesis on the right side. Death occurred after 1 developing ventricular fibrillation. 2

3 Misra et al. (1985) described another accide ntal occupational phosgene poisoning case. 4 A 30 year-old male was exposed to an undetermined concentration of phosgene and 5 immediately began coughing and experienced a se nse of suffocation and burning eyes. After 6 removal to fresh air and oxygen administration, he felt better. However, approximately 7.5 7 hours after the exposure, he was rushed to the emergency room with difficulty breathing. 8 Despite oxygen administration and antibiotic therapy, his condition deteriorated. He died 9 approximately 18 hours after exposure. An autopsy showed pulmonary edema and bronchiolar 10 necrosis, both of which were more severe in the lower lobes than the upper lobes of the lungs. 11

12 Hegler (1928) reported the effects of a phos gene accident that occurred in Hamburg, 13 Germany on May 20, 1928. Eleven metric tons of A pure phosgene @ were released from a 14 storage tank on a warm, dry, slightly windy day. Within a few hours, people as far as 6 miles 15 from the release site began reporting to hospitals. Three hundred people reported to hospitals 16 within a few days of the accident. Effects ranged from mild or moderate illness to death; ten 17 people were reported to have died. In general, exposed persons exhibited symptoms consistent 18 with other reported phosgene poisonings (headache, dizziness, nausea and vomiting, irritant 19 cough, and sickening-sweet taste followed by a latency period and then pulmonary symptoms). 20 Autopsies on six of the fatalities showed pulmonary effects in all cases. Fatty degeneration of 21 the kidneys, liver, and heart were observed in a few cases and were thought to be secondary to 22 the pulmonary damage. In an atypical case damage in the gray matter of the brain and spinal 23 cord, and hyperemia and signs of bleeding in the white matter were observed at autopsy. This 24 patient died 11.5 days post-exposure from a blood cl ot lodged in the lung. It was uncertain if 25 the extrapulmonary effects were due to phosgene exposure. 26

27 2.2. Nonlethal Toxicity 28

29 NIOSH (1976) performed two studies to determine the odor threshold of phosgene. In 30 the first, 56 military personnel were exposed to increasing phosgene concentrations until all 31 subjects could detect odor. The lowest detect able concentration was 0.4 ppm. Thirty-nine 32 percent of subjects could detect odor at 1.2 ppm , and 50% of subjects detected odor at 1.5 ppm. 33 In the other study, four subjects identified 1.0 ppm as the lowest concentration at which the 34
distinctive A new mown hay @ odor of phosgene could be detected. 35

36 In their literature review, Diller and Zante (1982) identified nonlethal effects from 37 phosgene exposure. Nonlethal information synthesized from this review is presented in Table 38

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TABLE 2. Acute Irritative Effects of Phosgene Exposure in Humans
Effect Phosgene Concentration
Throat irritation 3.1 ppm Ocular irritation 4.0 ppm Cough 4.8 ppm Severe eye and airway irritation 10 ppmPHOSGENE DRAFT REVISED 1: 10/2009 Page 12 of 73

Diller and Zante, 1982 1

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From the above data and from animal data for A initial lung damage, @ Diller and Zante 3 (1982) synthesized information for nonlethal effects of phosgene in humans (Table 3). 4

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TABLE 3. Effect of Phosgene Exposure in Humans
Effect Phosgene Exposure
Odor perception >0.4 ppm Odor recognition >1.5 ppm Ocular, nasal, throat, and bronchiolar irritation >3 ppm Initial lung damage >30 ppm-min Clinical pulmonary edema >150 ppm-min
Diller and Zante, 1982 6

7 2.2.1. Case Reports 8

9 A 30-year-old male was occupationally exposed to an unknown concentration of 10 phosgene (Stavrakis, 1971). After a short episode of coughing, he returned to work and 11 completed the final three hours of his shift. Approximately four hours post-exposure, he 12 presented at the emergency room with severe dyspnea, restlessness, chest pain, and persistent, 13 productive cough. Chest X-rays confirmed acute pulmonary edema. He was treated and 14 discharged free of symptoms five days after the phosgene exposure. 15

16 An investigator was exposed to an undetermined concentration of phosgene during an 17 experiment (Delephine, 1922). He entered the phosgene chamber A at frequent intervals @ over a 18 period of 45 minutes to take instrument readings . At first, he experienced only laryngeal and 19 conjunctival irritation, but as the phosgene concentration increased, he was forced to hold his 20 breath and not stay in the room for more than one minute. Toward the end of the experiment, 21 some phosgene escaped from the chamber. At this time, the investigator and a colleague 22 experienced a violent cough and began to run away. During their escape, both men had to stop 23 frequently due to the violent nature of their coughs. After exiting the contaminated area, both 24 individuals continued to cough for approximately 20 minutes. They then improved for three or 25 four hours after which they experienced a choking sensation that lasted approximately 24 hours. 26 Marked lassitude lasted for an additional few days, after which recovery appeared to be 27 complete. 28

29 Everett and Overholt (1968) discussed a 40 year-old man who received a A massive @ 30 phosgene exposure. His initial symptoms included coughing and burning of the eyes, which 31 subsided within 5 minutes. He was asymptomatic for the next two hours after which a hacking 32 cough began. Three hours after exposure, mild dyspnea was present, and 6 hours post-exposure 33 severe dyspnea and moist rales were observed. He was admitted to an intensive care unit 34 8 hours post-exposure and presented with anxiety, agitation, cyanosis, thirst, constant cough, 35 and severe pulmonary edema. By the fifth day in the hospital, he was asymptomatic, and by the 36 seventh day, pulmonary function and chest x-ray were normal. A two-year follow-up was 37
unremarkable. 38PHOSGENE DRAFT REVISED 1: 10/2009 Page 13 of 73

1 Regan (1985) described a phosgene release from a toluene diisocyanate plant. Fifteen 2 employees were exposed to an undetermined concentration of phosgene, resulting in the 3 hospitalization of four workers. Two of the four were released after an overnight observation. 4 The other two were in more serious condition. One of them, a 31-year-old male, had pulmonary 5 edema, rales in both lungs, and left chest pain 8 hours post-exposure. He was treated with 6 oxygen, bronchodilators, steroids, and antibiotics and returned to work 6 days after the accident. 7 His follow up was unremarkable. The second man, a 47 year-old smoker, presented with 8 dyspnea, bilateral rales, and pulmonary edema 11 hours post-exposure. He was also treated 9 with oxygen, bronchodialators, steroids, and antibio tics, but continued to deteriorate. He 10 remained critical for three days with low right-side heart pressure, low arterial pressure, hemo11 concentration, and leukocytosis. He was asymptomatic by 12 days post-exposure. He had mild 12 pulmonary obstruction four weeks after the acciden t; however, it is unclear if this was a result 13 of phosgene exposure or because of his smoking. 14

15 Longer-term effects from acute phosgene exposure have also been described. Galdston 16 et al. (1947a) described the late effects of phosgene poisoning in six workers (2 male, 4 female; 17 ages 31-50). These workers all experienced acute, accidental, occupational exposure to 18 phosgene, and experienced the typical effects of acute exposure to phosgene. Chronic clinical 19 findings present from 1 to 24 months post- exposure included rapid shallow breathing, and 20 changes in pulmonary function. However, no correlation was observed between the magnitude 21 of phosgene exposure or severity of acute effect s and severity of chronic symptoms. Galdston et 22 al. (1947a) attributed the severity of chronic symptoms to the subjects = psychological state. 23 Smoking habits were not reported and long-term follow up was not performed. 24

25 Galdston et al. (1947b) also examined five males (ages 24-50) who had repeated 26 occupational exposure to A small amounts @ of phosgene during the course of 1.5 to 3.5 years. 27 The subjects were examined with regard to pulmonary function and cardiac status. The subjects 28 exhibited transitory effects such as cough, shortness of breath on exertion, and pain or tightness 29 of the chest. These symptoms abated upon removal from phosgene exposure for several weeks. 30 Results suggested that although symptoms of chronic exposure to low concentrations of 31 phosgene are generally not as disabling as those from acute exposure, emphysema may develop 32 after chronic exposure. Also, pulmonary functi on effects are more severe after chronic low 33 level exposure than after recovery from a serious acute exposure. 34

35 Diller et al. (1979) examined 12 originally healthy workers three to nine years after 36 intoxication with phosgene (10 workers), nitric oxide (1 worker), or teflon smoke (1 worker). 37 Six of the 12 individuals complained of pulmonary symptoms for three years post-exposure, and 38 3 of the twelve showed slight to severe lung function effects. The severity of lung function 39 decrement correlated more closely with smoking ha bits than with the severity of chemical 40 intoxication. Diller et al. (1979) concluded th at originally healthy survivors of phosgene 41 intoxication recover fairly well over a period of years. However, individuals with preexisting 42 chronic bronchitis may suffer significant chroni c deterioration of lung function after acute 43 phosgene intoxication, as an additional observation over 25 years showed. The individual, a 44 light smoker who had mild chronic bronchitis since childhood, was exposed to phosgene and 45 smoke at age 35. He developed severe pulmonary edema and was hospitalized for 7 weeks 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 14 of 73

following the exposure. During the months following the exposure, his general condition 1 worsened and the bronchitis became more severe. After two years, pulmonary function (FEV 2 and VC) was decreased to 70% of normal. Ten years post-exposure, he developed pulmonary 3 emphysema, and VC and FEV were decreased to 50% of normal. 4

5 Herzog and Pletscher (1955) observed squamous metaplasia of the cilitaed bronchial 6 epithelium in two patients exposed to undetermined concentrations of phosgene. The 7 metaplasia was observed 3 months or three years post-exposure, respectively. 8

9 In a phosgene processing factory, phosgene concentrations were measured over an 8- 10 month period with a device capable of detec ting of 0-0.5 ppm phosgene (Henschler, 1971). 11 Positive values, of relatively short duration, were recorded only on 32 of 240 days: on 22 days, 12 0.05 ppm; on 6 days, between 0.06 and 0.1 ppm; on 3 days, between 0.1 and 0.5 ppm; on 1 day, 13 0.5 ppm (of short duration). For longer time periods, elevated concentrations were measured 14 on three occasions: twice for 3 hours, between 0.015 and 0.035 ppm and once for 1.5 hours, 15 0.35 ppm. The above described conditions produced no intoxication or effects on lung 16
function. 17

18 In another factory, use of a phosgene indicator badge revealed an average of 34 19 phosgene exposures per year during the period from 1978 to 1988 (Kaerkes, 1992). The 20 workforce contained approximately 200 individua ls ranging in age from <20 to 60 years. 21 Exposure concentrations ranged from <50 to 300 ppm. min. Below 50 ppm.min, no signs or 22 symptoms of phosgene toxicity were observed in 75/88 individuals; however, three cases of 23 temporary pulmonary edema were observed. 24

25 In another report, Sandall (1922) examined 83 British soldiers three years after 26 phosgene exposure. Shortness of breath upon exer tion (70%), cough with expectoration (54%), 27 tight feeling in chest (25%), sporadic giddiness (14%), and nausea (12%) were the most 28 frequently reported complaints. No physical lung abnormalities were noted in 53% of the men. 29

30 2.2.2. Epidemiologic Studies 31

32 Polednak (1980) studied a uranium processing plant where phosgene was produced as a 33 by-product of a chemical process in which UO 3 was combined with CCl 4 to produce UCl 4

. 34 Leaks and system failures resulted in the accidental release of phosgene into work areas. 35 Although extensive monitoring data were not available, it was determined that the average 36 exposure was below the detection limit of monitoring instruments used at that time. However, 37 there were 3 to 5 episodes daily when concentrations exceeded the 1 ppm exposure limit 38 recognized as the occupational standard of the time. 39

40 Approximately 30 years after exposure, there were no statistically significant increases 41 in mortality from overall cancer or cancers at specific anatomical sites, from diseases of the 42 respiratory system, or overall mortality noted in this cohort. However, the exposure period 43 covered by the study was short, the exposed groups were small, and exposure levels were not 44 well documented. Consequently, evidence presented in this study is inadequate to assess the 45 carcinogenicity of phosgene. 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 15 of 73

1 Polednak and Hollis (1985) reported a follow-up of the study discussed above. The 2 study update reported the mortality experience of individuals through the end of 1978 and 3 included 694 routinely exposed white male chemical workers, 97 acutely exposed chemical 4 workers, and 9280 controls. Vital status ascertainment for the routinely exposed group and the 5 controls was approximately 90% complete using Social Security Administration (SSA) records. 6 For the acutely exposed group SSA records as well as state death indexes were used to 7 ascertain vital status, which was approximately 92% complete. Five individuals in the routinely 8 exposed group, 9 in the acutely exposed group, and 72 controls were lost to follow-up. 9

10 Approximately 35 years after exposure to phosgene no increase in overall mortality or 11 mortality from cancer or respiratory disease was noted in this cohort. 12

13 NIOSH (1976) compared the medical records of 326 workers exposed to phosgene with 14 those of 6288 unexposed workers from the same plant. Personal air sample measurements at 15 this plant (20 min samples) showed phosgene concentrations ranging from undetectable to 16 0.02 ppm, with a 15 sample average of 0.003 ppm. Fixed-position air samples (20 min or 2 hr 17 collection) ranged from undectable to 0.13 ppm in 51/56 samples, and >0.14 ppm in 5/56 18 samples. There were no differences in pulmonary function or deaths attributable to respiratory 19 disease between the exposed and control populations. 20

21 2.3. Developmental/Reproductive Toxicity 22

23 Developmental/reproductive studies regarding acute human exposure to phosgene were 24
not available. 25

26 2.4. Genotoxicity 27

28 Genotoxic studies regarding acute human exposure to phosgene were not available. 29

30 2.5. Carcinogenicity 31

32 Polednak (1980) and Polednak and Hollis (1985) examined a cohort of chemical 33 workers exposed to chronic low levels of phosgene as well as daily exposures above 1 ppm. 34 Approximately 35 years after exposure to phosgene, no increase in overall mortality or 35 mortality from cancer or respiratory disease was noted. These studies are described in detail in 36 Section 2.2.2 (Epidemiologic Studies). 37

38 2.6. Summary 39

40 Although there is a paucity of acute human data containing known exposure 41 concentrations and times, reports of human phosgene poisonings present a relatively consistent 42 set of clinical effects and sequale. After acute phosgene exposure, brief (  20 min.) ocular and 43 throat irritation, cough, nausea and vomiting, and dizziness are experienced, followed by a 44 period (  24 hr) of apparent well being. After this clinical latent phase, cough accompanied by 45 expectoration, a sensation of pain or tightness of the chest, shortness of breath, and a choking 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 16 of 73

sensation are experienced. Clinical findings may include hemoconcentration, leukocytosis, 1 rales, and pulmonary edema. After recover y, rapid, shallow breathing, shortness of breath on 2 exertion, and a sense of decreased physical fitness may persist for months. Pulmonary 3 emphysema may occur with repeated exposure to phosgene. Epidemiology studies have shown 4 no increase in cancer in workers exposed to phosgene compared to controls. No information 5 concerning reproductive/developmental toxicity or genotoxicity was available. 6

7
3. ANIMAL TOXICITY DATA 8 3.1. Acute Lethality 9

3.1.1. Mouse 10

11 Zwart et al. (1990) exposed groups of five ma le and five female Swiss mice to varying 12 concentrations of phosgene for 5, 10, 30, or 60 minutes. The test atmosphere was monitored at 13 both the inlet and outlet of the glass exposure chambers by gas chromatography and infrared 14 analysis. Ten minute LC 50 values were 77 and 61 ppm for males and females, respectively. 15 Thirty minute LC 50 values were 18 and 11 ppm for males and females, respectively, and 16
60 minute LC 50 values were determined to be 9 and 5 ppm for males and females, respectively. 17

18 Cameron et al. (1942) exposed 20 mice to an average phosgene concentration of 0.86 19 ppm for five hours. Twelve mice were dead the next morning. Several other acute lethality 20 studies of phosgene in mice have been reported. However, these studies do not contain 21 experimental details such as strain or sex of mouse, number of animals exposed, or analytical 22 methodology. These values, in addition to those of Zwart et al. (1990), are presented in Table 23

4. 24

25

TABLE 4. Acute Lethality of Phosgene in Mice

Time (Minutes) LC 50 (ppm) Reference
1 850 Chasis, 1944

1 3300 Moor and Gates, 1946 5 33 Kawai, 1973 10 77 (male); 61 (female) Zwart et al., 1990 15 15 Cameron and Foss, 1941 30 18 (male); 11 (female) Zwart et al., 1990 30 5.1 Kawai, 1973 60 9 (male); 5 (female) Zwart et al., 1990

26

3.1.2. Rats 27

28 Five male and five female young adult Wistar rats/group were exposed nose-only to 29 phosgene gas in a GLP acute lethality study (Pauluhn, 2006a). Rats were exposed for 10, 30, 60 30 and 240 minutes, and animals were examined for up to 2 weeks post-exposure. Subgroups of 31 eight male rats/group were exposed for 30 minutes to 0, 0.11, 0.29, 3.3, 6.1, or 11.8 ppm 32 phosgene and one additional group was exposed for 10 min. to 52 ppm to measure respiratory 33 function. The following parameters were measured in nose-only animal restrainers with 34 pneumotachographs and differential pressure transducers fitted onto a plethysmograph: 35PHOSGENE DRAFT REVISED 1: 10/2009 Page 17 of 73

respiratory rate (RR), tidal volume (TV), respir atory minute volume (MV), peak inspiratory and 1 expiratory time (ET) and average duration of the apnea period (AP). 2

3
Once the LC 50 s were established and physiological data were generated, an LC 01 was 4
calculated. Then, thirty male rats were exposed once to 1.0 ppm phosgene for 240 minutes 5 (concentration in the range of the estimated LCt 01 ) and were sacrificed on post-exposure days 1, 6 7, 14 or 28. Bronchoalveolar lavage fluid was examined in six rats/sacrifice, and an additional 7 six rats were examined for histopathology on day 28 post-exposure. 8

9 For all exposures, an aluminum nose-only chamber was used that consisted of two 10 segments with a total of 40 exposure ports at the perimeter. Each segment had dimensions as 11 follows: inner diameter- 14 cm.; outer diameter- 35 cm; height- 25 cm and an internal volume 12 about 3.8L. All airflows were monitored and adjusted continuously with calibrated flow 13 controllers. Target concentration was achieved by dilution cascades prior to entering the 14 directed-flow nose-only chamber. The supply airflow was 30 L/min and maintained an airflow 15 rate of 0.75 L/min per exposure port. Scrubbing devices were used for the exhausted air. The 16 concentration of phosgene gas was calculated nominally and measured analytically by gas 17 chromatography from test atmosphere samples taken from the vicinity of the breathing zone. 18

19
Combined male and female LC 50 values were 62.5, 13.5, 7.7, and 2.1 ppm for 10, 30, 20 60 and 240 min, respectively. Most mortality occurred within 24 hours. Clinical signs 21 observed included labored breathing, rales, lacrimation, cyanosis and decreased body weight. 22 Necropsy results showed grayish, distended lungs, edema, a foamy exudate in the trachea and a 23 few pulmonary hemorrhages. An increase in apnea time (AT) and transiently decreased 24 respiratory minute volumes were observed at 0.29 ppm and above; these effects leveled off after 25 an exposure duration longer than 10-15 minutes. In the thirty rats exposed to 1.0 ppm for 240 26 minutes, no mortality occurred. Lung weight and bronchoalveolar lavage (BAL) protein, PMNs 27 and total cell counts were all significantly (p<0.01 or 0.05) increased compared to controls on 28 post-exposure day 1, with most values similar to those of controls by post-exposure day 14. 29 Histopathological examination at 28 days post-exposure showed minimal to slight 30 hypercellularity in the terminal bronchioles, fo cal septal thickening, and no edema or fibrin. 31 Sirius red staining of the lungs showed no increased deposition of collagen. Table 5 below 32 summarizes mortality data from the study. 33

34PHOSGENE DRAFT REVISED 1: 10/2009 Page 18 of 73

TABLE 5. Acute Lethality Data in Rats Exposed to Phosgene
Mortality LC 50 BMCL 05 BMC 01 Concentration (ppm) Exposure
duration

(min) M F

41.1 10 2/5 1/5

44.8 10 0/5 0/5

52.3 10 1/5 1/5

61.9 10 3/5 3/5 62.5 ppm 24.3 ppm 32.6 ppm

12.6 30 3/5 1/5

13.4 30 3/5 1/5

16.7 30 5/5 5/5

21.4 30 5/5 4/5 13.5 ppm 5.0 ppm 7.4 ppm

0 60 0/5 0/5

7.4 60 2/5 2/5

9.7 60 5/5 4/5

11.8 60 5/5 5/5 7.7 ppm 3.9 ppm 5.3 ppm

2.2 240 5/5 1/5

2.7 240 5/5 4/5 2.1 ppm - -

Pauluhn, 2006a
1

2 Zwart et al. (1990) exposed groups of five male and five female Wistar rats to varying 3 concentrations of phosgene for 5, 10, 30, or 60 minutes. The test atmosphere was monitored at 4 both the inlet and outlet of the glass exposure chambers by gas chromatography and infrared 5 analysis. The ten minute LC 50 value was 80 ppm, while the thirty and 60 minute LC 50 values 6 were 20 and 12 ppm, respectively. 7

8 A total of 118 male Wistar rats were exposed to 0.5 to 4.0 ppm phosgene for 5 minutes 9 to 8 hours (Rinehart, 1962; Rinehart and Hatch, 1964) . The exposures were varied to give CT 10 products between 12 and 360 ppm-min and were carried out in 1700 L wooden exposure 11 chambers, operating at a constant ventilation rate of 1000 L/min. The chamber surfaces were 12 lacquered, and thus, potential loss of phosgene by reaction with the wooden surface was 13 minimized. This system provided for air A turn-over @ every 2 minutes and a 99% equilibrium 14 time of 8 minutes. Air samples were taken frequently during exposures, and adjustments were 15 made when necessary to maintain constant phosgene concentrations. An L(CT) 0 of 180 ppm16 min, a 75 min LC 50 of 4 ppm, and a 125 min LC 100 of 4 ppm were determined. The authors 17
concluded that different combinations of con centration and time exposure giving equal products 18 of C x T constitute equally effective doses. 19

20 Several other acute lethality studies of phosgene in rats have been reported. However, 21 as was the case with the mice, these studies do not contain experimental details such as strain or 22 sex, number of animals exposed, or analytical methodology. These studies are summarized in 23
Table 6. 24

25PHOSGENE DRAFT REVISED 1: 10/2009 Page 19 of 73

TABLE 6. Acute Lethality of Phosgene in Rats

Strain Number/sex Exposure time (min) Concentration (ppm) Endpoint Reference

NR NR 10 35 LC 20 Shils, 1943

NR NR 10 60 LC 40 Shils, 1943

NR NR 1 1625 LC 50 Chasis, 1944

NR 44/NR 10 38-75 LC 50 Box and Cullumbine, 1947a

NR NR 12 30 LC 50 Chasis, 1944

NR NR 15 35 LC 50 Cameron and Foss, 1941

NR NR 20 15 LC 50 Kimmerle and Diller, 1977

Wistar 40/NR 30 10-15 LC 75 Henschler and Laux, 1960

NR NR 20 25 LC 50 Rothlin, 1941

NR NR 12 85 LC 60 Shils, 1943

NR NR 10 40 LC 70 Kimmerle and Diller, 1977

NR 32/NR 10 39-103 LC 75 Box and Cullumbine, 1947a

Wistar 40/NR 20 25 LC 50 Henschler and Laux, 1960

NR NR 3 220 LC 100 Winternitz et al., 1920

NR 12/NR 10 147 LC 100 Box and Cullumbine, 1947a

NR 10/NR 13 73 LC 100 Schultz, 1945

NR NR 20 37 LC 100 Rothlin, 1941

NR NR 30 22 LC 100 Winternitz et al., 1920
NR=Not Reported
1

2 Box and Cullumbine (1947b) investigated phosgene-induced lethality in rats after first 3 receiving an exposure to a non-lethal concentration of phosgene. Rats were divided into two 4 groups (12/group). Half of the groups were exposed to 19.2 ppm phosgene for 10 minutes and 5 the other half served as a control group. Five days later, the pre-exposed and control rats were 6 exposed to 55.2 , 60, 75.6, and 105.6 ppm of phosgene for 10 minutes. These rats were then 7 observed for the next 48 hours for deaths. The pretreated rats had a reduced percentage of 8 mortality (33%) compared to the control animals (74%). Thus, partial protection from 9 phosgene-induced lethality was obtained by the phosgene pretreatment. 10

11 3.1.3. Guinea Pigs 12

13 The few acute lethality studies of phosgene in guinea pigs do not contain experimental 14 details such as strain or sex, number of animals exposed, or analytical methodology. These less 15 than adequate studies are summarized in Table 7. 16

17PHOSGENE DRAFT REVISED 1: 10/2009 Page 20 of 73

TABLE 7. Acute Lethality of Phosgene in Guinea Pigs
Exposure Time (minute) Concentration (ppm) Endpoint Reference

1 672 LC 50 Chasis, 1944

15 32 LC 50 Underhill, 1920

30 18 LC 50 Chasis, 1944

30 141 LC 50 Moor and Gates, 1946

9 85 LC 99 Coman et al., 1947

3 220 LC 100 Winternitz et al., 1920

30 20 LC 100 Winternitz et al., 1920

20 77 LC 100 Ong, 1972

1

2

3.1.4. Rabbits 3

4 As was the case with guinea pigs, the few acute lethality studies of phosgene in rabbits 5 do not contain experimental details such as strain or sex, number of animals exposed, or 6 analytical methodology. These less than adequate studies are summarized in Table 8. 7

8

TABLE 8. Acute Lethality of Phosgene in Rabbits
Exposure Time (minute) Concentration (ppm) Endpoint Reference

30 17 LC 40 Frosolono, 1977

1 3200 LC 50 Moor and Gates, 1946

15 187 LC 50 Underhill, 1920

20 110 LC 50 Cameron and Courtice, 1946

20 20 LC 50 Laquer and Magnus, 1921

30 100-135 LC 70 Halpern et al., 1950

30 93 LC 75 Frosolono, 1976

30 82 LC 90 Shils, 1943

35 151 LC 99 Coman et al., 1947

15 220 LC 100 Winternitz et al., 1920

30 110 LC 100 Winternitz et al., 1920

9

10
3.1.5. Cats 11

12 Wirth (1936) reported no deaths in cats exposed to 1.8 ppm phosgene for 470 minutes. 13
A 1 min. LC 50 of 1482 ppm phosgene was reported by Moor and Gates (1946), while a 15 min 14

LC 50 of 80 ppm was reported by Underhill (1920). No details such as number, sex, strain of cat, 15 or methodology was provided in any of these studies. 16

17 3.1.6. Dogs 18

19 Meek and Eyster (1920) exposed eight mongrel dogs (sex not specified) to 80 - 100 ppm 20 phosgene for 30 minutes. All eight died within 24 hours post-exposure. Pulmonary edema with 21 some evidence of cardiac effects was observed at necropsy. 22

23PHOSGENE DRAFT REVISED 1: 10/2009 Page 21 of 73

Additional dog lethality information is presented in Table 9. 1

2

TABLE 9. Acute Lethality of Phosgene in Dogs

Strain Number/sex Exposure
time (minute) Concentration (ppm) Endpoint Reference

NR 12/NR 10 110 LC 25 Cameron and Courtice, 1946

NR NR 1 2100 LC 50 Chasis, 1944

NR NR 10 45 LC 50 Kimmerle and Diller, 1977

NR 24/NR 15 60-70 LC 50 Underhill, 1920

NR NR 20 502 LC 50 Chasis, 1944

NR 6/NR 30 100-175 LC 50 Patt et al., 1946

NR NR 30 78 LC 55 Postel and Swift, 1945 Mongrel 18/NR 3 745-880 LC 70 Coman et al., 1947

NR 94/NR 20 135 LC 70 Freeman et al., 1945

NR 42/NR 30 98 LC 70 Postel and Swift, 1945 Mongrel 15/M,F 30 124 LC 90 Schultz, 1945 Mongrel 32/NR 10 39-103 LC 75 Box and Collumbine, 1947 Mongrel NR 3 734 LC 99 Coman et al., 1947 Mongrel NR 30 90 LC 99 Coman et al., 1947

NR=Not Reported

3

4
3.1.7. Goats 5

6 Karel and Weston (1947) reported a 10 min. LC 50 of 250 ppm phosgene for a group of 7 30 female and 1 male goat, while Underhill (1920) reported a 15 min LC 50 of 180 ppm for a 8 group of 61 goats. All goats died when exposed to 8750 ppm phosgene for 1 minute (Tobias, 9 1945), 500 ppm for 3 minutes, or 110 ppm phosgene for 30 minutes (Winternitz et al., 1920). 10 No further experimental details were available. 11

12 3.1.8. Sheep 13

14
A 10-minute LC 50 value of 333 ppm phosgene was determined from exposing groups of 15 two Dorset crossbred wethers to 135, 240, 427, or 758 ppm phosgene for 10 minutes, followed 16 by a 24-hour observation period (Keeler et al., 1990b). Animals that died displayed a mixture 17 of stringy mucous and frothy white material from the proximal trachea to the smaller 18 bronchioles that filled the alveoli, perivascular spaces, and interlobular septa. Sheep that 19 survived the 24-hour postexposure period were noted to have airways with scant amounts of 20 mucus and frothy white material and mild to moderate alveolar edema. 21

22
3.1.9. Non-human Primates 23

24 Chasis (1944) reported a 1 minute LC 50 of 240 ppm phosgene for a group of monkeys. 25 The strain, sex, or number of animals was not reported. A 1 minute LC 50 of 500 ppm was 26 reported for 19 male and 18 female Rhesus monkeys (Weston and Karel, 1947). Moor and 27PHOSGENE DRAFT REVISED 1: 10/2009 Page 22 of 73

Gates (1946) found that all monkeys died when exposed to 1087 ppm phosgene for 1 minute. 1 No other experimental details were available for either study. 2

3 3.2. Nonlethal Toxicity 4
3.2.1. Mice 5

6 Forty male CD-1 mice/group were exposed whole body for 20 minutes to either air or 7 8 ppm phosgene (Sciuto et al., 2001). The chamber had a total volume of 15.8 L and a flow rate 8 of 20 L/min. Phosgene was collected at the chamber’s outflow and concentrations were 9 measured using an infrared spectrometer. Arterial blood samples were taken from the mice at 1, 10 4, 8, 12 and 24 hours after the start of the exposure. Animals were sacrificed after blood was 11 obtained and lung edema was estimated from lung wet weight/lung dry weight ratios 12 (WW/DW). The exposure at 8 ppm caused pronounced acidosis indicated by decreasing arterial 13 pH; this effect was significant (p<0.05) 8 to 12 hours after exposure. In the surviving mice, 14 arterial pH was similar to that of controls by 24 hours. Arterial oxygen partial pressure (PO 2 ) 15
and O 2 saturation also decreased compared to controls beginning at 4 hours post-exposure. 16 These parameters were also similar to controls by 24 hours. Partial pressure for carbon dioxide 17 followed a similar path except it increased after exposure with the most significant increase at 18 8 hours. The lung WW/DW ratio in treated mice increased significantly (p<0.05) compared to 19 that of controls at all time points starting at 4 hours with the greatest increase at 8 hours post20 exposure (52%). 21

22 In another study, male CRL:CD-1 (ICR)BR mice were exposed whole-body to either air 23 or 22 ppm phosgene for 20 minutes and were sacrificed immediately post-exposure for 24 bronchoalveolar lavage (BAL) fluid analysis (Sciuto, 1998). The BAL fluid was analyzed for 25 total glutathione (GSH), lipid peroxidation thiobarbituric acid reactive substances (TBARS) and 26 protein. Lung edema was also assessed by obtai ning lung wet weight and lung wet/dry ratios. 27 The study did not report any deaths during expos ure. There was a statistically significant 28 (p<0.001) increase in protein levels in the BAL. 29

30 Hatch et al. (1986) exposed Swiss albino mice (8/group) to 0, 0.1, 0.2, 0.5, or 1 ppm 31 phosgene for four hours in an 11.3 ft 3 Rochester-type chamber. The phosgene was mixed with 32 filtered room air before the metering orifice of the chamber and introduced into the chamber 33 airstream. The chamber airstream had a flow rate of 1 chamber volume/minute, and the 34 chamber air was sampled every 10 minutes. Phosgene concentrations were first determined by 35 gas chromatography, and an infrared analyzer was used for a second check. Actual chamber 36 concentrations were within 2 to 6% of target concentrations. Eighteen to 20 hours post37 exposure, the lungs were lavaged and analyzed fo r lavage fluid protein (LFP), an indicator of 38 pulmonary edema. The LFP findings were 292  18, 302  21, 941  105, 1302  149, or 39

2168  167 (units not provided) for 0, 0.1, 0.2, 0.5, or 1 ppm, respectively. The lowest 40 exposure concentration producing a statistically significantly (p<0.05) altered protein 41 concentration was 0.2 ppm. 42

43 In another study, Illing et al. (1988) exposed groups of 37-39 female CD-1 mice to 0.1 44 to 0.5 ppm phosgene for 4 hours. Animals were exposed in stainless steel exposure chambers. 45 Phosgene concentrations were monitored primarily by gas chromatography and double checked 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 23 of 73

by infrared analysis. There was a significant (p<0.05) increase in pentobarbital-induced 1 sleeping time in mice exposed to 0.15 to 0.5 ppm phosgene compared with air controls. No 2 significant differences were observed in cytochro me P450 levels, body weights, or liver weights 3 between phosgene exposed mice and air controls. 4

5 Box and Cullumbine (1947b) exposed a group of 37 mice to 144 ppm phosgene for an 6 unspecified period of time. Sub-groups of four or five of these mice were sacrificed on 7 postexposure days 1, 2, 3, 4, 5, 7, 10, or 14. A hi stopathological examination was performed on 8 the lungs of these animals. Varying degrees of edema, patches of leucocytic infiltration, and 9 bronchial and bronchiolitic epithelia being lifted by edema were observed on post-exposure 10 day 1. More severe edema and collapsed lungs with leukocytic infiltration were observed on 11 post-exposure days 2-5. The lungs of the remaining mice were essentially normal by post12 exposure days 10 through 14. 13

14

3.2.2. Rats 15

16 Adult male Wistar rats were exposed nose-only to phosgene gas in a GLP inhalation 17 study for 30 or 240 minutes (Pauluhn, 2006b). The 30 minute exposures were to 0, 0.2, 0.5, 1.0, 18 2.0 or 4.0 ppm and the 240 minute exposures to 0, 0.05, 0.1, 0.2, 0.4 or 1.0 ppm. Animals were 19 observed for up to 84 days post-exposure. Chamber concentrations were monitored 20 continuously by sampling from ports throughout the chamber using either an infrared analyzer 21 or toxic gas paper tape monitor. Test atmospheres were also characterized using gas 22 chromatography. No deaths occurred in any groups. 23

24 Six rats/group were sacrificed for bronchoalveolar lavage (BAL) and lung weight on 25 post-exposure days 1, 3, 7, 14 and 84 and the rats exposed to 1 ppm for 4 hours were sacrificed 26 on post-exposure days 1, 7, 14 and 28. In addition, 6 rats, not lavaged, were used for 27 histopathological analysis on days 28 and 84. Clin ical signs of irregular and labored breathing, 28 tachypnea and decreased body weight were observed in the rats exposed to ≥ 2 ppm for 30 29
minutes and ≥ 0.2 ppm for 240 minutes. At necropsy, rats exposed to 4.0 ppm for 30 minutes 30
and ≥ 0.4 ppm for 240 minutes had noncollapsed lungs, focal discolorations and enlarged lung31 associated lymph nodes on post-exposure day 1 and to a lesser extent on days 3 and 7. Lung 32 edema was observed in 3/6 rats exposed to 1.0 ppm for 240 minutes on post-exposure day 1. 33

34 Histopathology performed on day 84 showed similar lesions between treated and control 35 rats in the lungs, but at day 28 in the 1.0 ppm group (240 minutes), 5/6 rats had minimal to 36 slight hypercellularity of the terminal bronchioles with occasional peribronchial inflammatory 37 infiltrates and septal thickening. There was no evidence of persistent inflammatory responses 38 such as chronic pneumonia. Statistically signi ficant (p<0.01 or 0.05) increases in lung weight 39 were observed in the rats treated with 4.0 ppm for 30 minutes or ≥ 0.4 ppm for 240 minutes. 40 The BAL fluid protein levels and polymorphonucl ear leukocytes (PMNs) increased starting on 41 post-exposure day 1 in rats exposed to ≥ 2 ppm for 30 minutes or ≥ 0.2 ppm for 240 minutes. 42

43 By 7 days post-exposure, parameters were similar to those of controls except in the 44 highest concentration animals (1.0 ppm x 240 minut es). Tables 10 and 11 show the findings of 45 lung wt/bwt ratio and in the BAL fluid. 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 24 of 73

1

TABLE 10. Group Means (±SD) of Findings in Rats Exposed for 4 Hours to Phosgene

Lung wt/body wt (mg/100g ) Protein in BAL (g/L) Collagen in BAL (mg/L) Neutrophilic granulocytes in BAL (%)
Day 1

Control

0.1

0.2

0.4

1.0 466.0 ± 13.9

479.2 ± 29.0

521.3 ± 40.0
571.5** ± 19.5
1023.0** ± 162.0 0.194 ± 0.012

0.214 ± 0.037
0.905* ± 0.690
1.89** ± 0.65
13.6** ± 3.0 10.0 ± 2.7

13.7 ± 3.9

61.5 ± 81.1
141.7** ± 73.8
3203.0** ± 870 0.111 ± 0.172

0.500 ± 0.459
4.00** ± 1.52
7.33** ± 3.80
36.9** ± 7.4 Day 3

Control

0.1

0.2

0.4

1.0 453.5 ± 15.8

472.2 ± 14.8

472.8 ± 21.2
536.9** ± 18.8

– 0.190 ± 0.075

0.179 ± 0.025

0.216 ± 0.025
0.378* ± 0.084

– 10.6 ± 1.8

7.32 ± 3.00

9.00 ± 1.75
35.6** ± 15.5

– 0.222 ± 0.272

0.167 ± 0.408
0.444* ± 0.544

5.83 ± 3.32

– Day 7

Control

0.1

0.2

0.4

1.0 438.4 ± 16.5

429.0 ± 13.4

432.6 ± 20.2

464.3 ± 20.7
627.8** ± 54.7 0.163 ± 0.022

0.169 ± 0.008

0.183 ± 0.029

0.175 ± 0.026

0.302 ± 0.082 10.0 ± 5.3

9.97 ± 4.63

11.9 ± 3.8

14.2 ± 3.7

49.3 ± 5.0 0.222 ± 0.404

0.167 ± 0.183

0.389 ± 0.328

0.167 ± 0.279
0.722* ± 1.611 Day 28

Control

0.1

0.2

0.4

1.0 402.7 ± 12.0

420.6 ± 20.7

420.1 ± 16.9
431.4* ± 9.2
438.3* ± 15.8 0.223 ± 0.025

0.204 ± 0.023

0.183 ± 0.020

0.212 ± 0.016

0.195 ± 0.026 11.5 ± 3.2

12.6 ± 3.8

14.7 ± 3.2
13.4* ± 1.8

13.9 ± 1.8 0.278 ± 0.251

0.111 ± 0.272

0.111 ± 0.172

0.222 ± 0.344

0.000 ± 0.000 Day 84

Control

0.1

0.2

0.4

1.0 334.6 ± 17.2

321.8 ± 13.2

324.0 ± 21.5

320.6 ± 23.3

– 0.243 ± 0.025

0.257 ± 0.008

0.268 ± 0.032

0.276 ± 0.024

– 10.3 ± 2.5

15.6 ± 4.7
21.4** ± 5.1

10.2 ± 2.8

– 0.278 ± 0.328

0.111 ± 0.272

0.278 ± 0.251

0.000 ± 0.000

–

a Data from Pauluhn, 2006b. * Statistically significant at p<0.05 or ** p<0.01 2

3PHOSGENE DRAFT REVISED 1: 10/2009 Page 25 of 73

TABLE 11. Group Means (±Sd) of Findings In Rats Exposed for 30 Minutes to Phosgene

Lung wt/body wt (mg/100g ) Protein in BAL (g/L) Collagen in BAL (mg/L) Neutrophilic granulocytes in BAL (%)
Day 1

Control***

0.2

0.5

1.0

2.0

4.0 466.0 ± 13.9

475.2 ± 25.2

469.1 ± 11.0

483.0 ± 26.5

495.3 ± 21.6
561.4** ± 34.1 0.194 ± 0.012

0.169 ± 0.020

0.181 ± 0.031

0.271 ± 0.064
0.685** ± 0.083

2.24** ± 1.01 10.0 ± 2.7

12.2 ± 2.1

16.5 ± 4.8

9.67 ± 3.37
29.9* ± 4.2

250.3** ± 229.2 0.111 ± 0.172

0.056 ± 0.136

0.111 ± 0.172

0.500 ± 0.506
1.44** ± 0.69

8.00** ± 3.14 Day 3

Control***

0.2

0.5

1.0

2.0

4.0 453.5 ± 15.8

453.5 ± 11.9

452.0 ± 10.4

464.2 ± 6.1

475.3 ± 19.6
538.6** ± 31.7 0.190 ± 0.075

0.184 ± 0.029

0.184 ± 0.023

0.190 ± 0.022

0.252 ± 0.057

0.349 ± 0.207 10.6 ± 1.8

13.3 ± 1.9

10.5 ± 3.4

13.7 ± 3.0

13.7 ± 6.0

22.4 ± 16.9 0.222 ± 0.272

0.278 ± 0.328

0.056 ± 0.136

0.056 ± 0.136

2.39 ± 3.19

7.22 ± 10.36 Day 7

Control***

0.2

0.5

1.0

2.0

4.0 438.4 ± 16.5

437.1 ± 27.3

421.6 ± 15.7

441.4 ± 22.7

445.0 ± 12.7

4..62 ± 11.4 0.163 ± 0.022

0.197 ± 0.019

0.198 ± 0.027

0.196 ± 0.016

0.169 ± 0.023

0.174 ± 0.024 10.0 ± 5.3

12.2 ± 3.6

10.3 ± 4.6

12.6 ± 2.2

11.3 ± 2.5

10.0 ± 4.9 0.222 ± 0.404

0.611 ± 0.647

0.111 ± 0.172

0.167 ± 0.279

0.222 ± 0.272

0.278 ± 0.443 Day 28
Control***

0.2

0.5

1.0

2.0

4.0 402.7 ± 12.0

407.9 ± 19.6

399.7 ± 18.2

385.3 ± 15.4
436.1* ± 12.4

418.1 ± 20.1 0.223 ± 0.025

0.218 ± 0.015

0.210 ± 0.027

0.195 ± 0.024

0.206 ± 0.019

0.206 ± 0.024 11.5 ± 3.2

13.3 ± 4.7

12.3 ± 4.9
12.4* ± 2.9

11.9 ± 3.7

19.4 ± 4.2 0.278 ± 0.251

0.389 ± 0.491

0.167 ± 0.279

0.278 ± 0.534

0.444 ± 0.779

0.167 ± 0.279 Day 84

Control***

0.2

0.5

1.0

2.0

4.0 334.6 ± 17.2

324.6 ± 13.7

336.4 ± 12.8

328.2 ± 15.7

330.3 ± 10.9

327.1 ± 9.8 0.243 ± 0.025

0.298 ± 0.130

0.248 ± 0.020

0.236 ± 0.016

0.289 ± 0.020

0.262 ± 0.016 10.3 ± 2.5

15.3 ± 5.1

14.3 ± 4.8
21.8** ± 5.0

12.4 ± 2.6

14.6 ± 2.7 0.278 ± 0.328

0.056 ± 0.136

0.056 ± 0.136

0.056 ± 0.136

0.200 ± 0.298

0.167 ± 0.279

a Data from Pauluhn, 2006b. * Statistically significant at p<0.05 or ** p<0.01 *** Control (0 ppm) exposure was 4-hour duration. 1

2 Male Sprague-Dawley rats were exposed whole-body to either air or 22 ppm phosgene 3 for 20 minutes and were sacrificed immediately post-exposure for bronchoalveolar lavage 4 (BAL) fluid analysis (Sciuto, 1998). The BAL was analyzed for total glutathione (GSH), lipid 5 peroxidation thiobarbituric acid reactive substances (TBARS) and protein. Lung edema was 6 also assessed by obtaining lung wet weight and lung wet/dry ratios. The study did not report 7 any deaths during exposure. There was a statis tically significant (p<0.001) increase in protein 8
levels in the BAL. 9

10 A total of 118 male Wistar rats were exposed to 0.5 to 4.0 ppm phosgene for 5 minutes 11 to 8 hours (Rinehart, 1962; Rinehart and Hatch, 1964) . The exposures were varied to give CT 12 products between 12 and 360 ppm-min and were carried out in 1700 L wooden exposure 13 chambers, operating at a constant ventilation rate of 1000 L/min. The chamber surfaces were 14PHOSGENE DRAFT REVISED 1: 10/2009 Page 26 of 73

lacquered, and thus, potential loss of phosgene by reaction with the wooden surface was mini1 mized. This system provided for air A turn-over @ every 2 minutes and a 99% equilibrium time 2 of 8 minutes. Air samples were taken frequently during exposures, and adjustments were 3 made when necessary to maintain constant phosgene concentrations. In addition to the lethality 4 data presented in Section 3.1.2, several conclusions were also drawn concerning non-lethal 5 endpoints. First, the CT product appears to be a valid way to express pulmonary irritation due 6 to phosgene exposure. This is based on the finding of equal degrees of respiratory response, as 7 measured by reduction in pulmonary gas exchange capacity, from exposures to various 8 combinations of C and T that yield the same CT product. Second, there is no decrease in 9 pulmonary performance from exposures less than CT= 30 ppm-min, but above this level, gas 10 exchange capacity decreases directly with a log increase in CT. Finally, for low level exposures 11 (below CT= 100), the major site of action is the respiratory bronchioles, while above this level, 12
the alveoli are involved. 13

14 In a later publication of the above experiment (Gross et al., 1965), pulmonary pathology 15 from the phosgene exposed-rats was described. Exposure to high concentrations of phosgene 16 (2 ppm for 90 min) produced chemical pneumonia, while exposure to lower concentrations 17 produced A chronic pneumonitis. @ The degree of pneumonitis produced by phosgene was rated 18 as slight, moderate, or severe. Slight pneumonitis was defined as mural thickening of respira19 tory bronchioles with involvement of adjacent alveoli. Moderate pneumonitis was defined as 20 alveolar involvement in a peribronchiolar zone that extends no more than one-third of the 21 distance to the next bronchiole. Severe pneumonitis was defined as mural thickening of the 22 respiratory bronchioles accompanied by obliteration of adjoining alveoli and air spaces con23 taining desquamated alveolar cells. The lowest 1-hr phosgene concentration producing 24 moderate pneumonitis was 0.8 ppm. The same effect occurred with 1-hr exposures to 0.9, 2.5, 25 or 3 ppm phosgene. This occurred in 2 of 3 rats, with the third rat displaying slight 26 pneumonitis. 27

28 Hatch et al. (1986) exposed Sprague-Dawley rats (8/group) to 0, 0.1, 0.2, 0.5, or 1 ppm 29 phosgene for four hours. The exposure system and parameters are similar to those described in 30 Section 3.2.1 (Hatch et al., 1986). Actual chamber concentrations were within 2 to 6% of target 31 concentrations. Eighteen to 20 hours post-exposure, the lungs were lavaged and analyzed for 32 lavage fluid protein (LFP). The LFP findings were 340  38, 258  18, 506  54, 1642  116, 33

or 2471  125 (units not provided) for 0, 0.1, 0.2, 0.5, or 1 ppm, respectively. The lowest 34 exposure concentration producing a significantly (p<0.05) increased protein concentration was 35 0.2 ppm. 36

37 Male Sprague-Dawley rats were exposed to 0, 0.125, 0.25, 0.5, or 1 ppm phosgene for 38 four hours and sacrificed on Day 0, 1, 2, or 3 pos t-exposure (Currie et al., 1987a). Animals 39 were exposed in 0.32 m 3 Rochester-type inhalation chambers. The air flow was 0.32 m 3 /min, 40 and the gas mixture passed downward through stai nless steel wire cages holding the animals 41 and was exhausted at the bottom through a water scrubber. Temperature in the chambers was 42

23.0  3.4 o C and humidity was 60  10% during exposures. The chambers were monitored by 43 both infrared analysis and gas chromatography continuously during exposure, and even 44 phosgene distribution was assured by sampling from various areas of the exposure chamber. 45 Measured phosgene concentrations were within 2-6% of target concentrations. Exposure- 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 27 of 73

related changes were observed in body weights, we t lung weights, LFP concentrations, and total 1 cell count and differential cell count in lavage fluid. Body weights were decreased immediately 2 after exposure through Day 2 for the 0.5 and 1 ppm exposure groups. Wet lung weights were 3 increased in the 0.5 ppm exposure group on postexposure Days 1, 2, and 3 and in the 1 ppm 4 exposure group immediately after exposure and on postexposure Days 1, 2, and 3. The relative 5 wet lung to body weight ratios were increased i mmediately after exposure and on Days 1, 2, and 6 3 in the 0.5 and 1 ppm exposure groups. LFP concentrations were increased in the 0.25 ppm 7 exposure group on Day 1 and in the 0.5 and 1 ppm exposure groups immediately after exposure 8 and on Days 1, 2, and 3. Total cell counts in lavage fluid were elevated in the 1 ppm exposure 9 group on Days 2 and 3. Percentage of polymor phonuclear leukocytes were increased in the 10 0.25 ppm exposure group on Days 1 and 2 and in the 0.5 and 1 ppm exposure groups on Days 1, 11 2, and 3. The LFP and cellular parameters had their peak effect on day 1 post-exposure and had 12 begun a return to control values by day 3 post-exposure, suggesting that the pulmonary damage 13 was reversible or rapidly repairable. 14

15 In another study, Currie et al. (1987b) exposed male Sprague-Dawley rats to 0, 0.05, 16 0.125, 0.25, 0.5, or 1 ppm phosgene for four hours. The exposure system and parameters are 17 similar to those described in Currie et al. (1987a ). Animals were sacrificed immediately after 18 exposure and at days 1, 2, and 3 post-exposure. The ATP concentrations in lungs were 19 significantly (p<0.05) decreased immediately after exposure at all exposure concentrations. 20 The 1 ppm exposure group also had decreased ATP concentrations on Day 1 and increased ATP 21 concentrations on Days 2 and 3. All other exposure groups had ATP concentrations similar to 22 control values on Days 1, 2, and 3. LFP concentr ations were only measured immediately after 23 exposure and were linearly increased at 0.25, 0.5, and 1 ppm phosgene. 24

25 Frosolono and Pawlowski (1977) exposed anesthetized male CFE Carworth rats to 0, 26 100, 200, or 430 ppm phosgene for approximately 10 minutes. Animals were exposed in a 364 27 L glass and stainless-steel chamber, and phosgene concentrations were estimated with a 28 phosgene detector tube. The authors = stated that A the analytical method for the determination 29 of phosgene concentrations is not highly pr ecise.... and concentrations given should be 30 considered putative or nominal. @ Groups of 6 to 8 rats/concentration were sacrificed 0, 30, 60, 31 or 90 minutes after exposure. No percentage change of lung water (used as a measure of 32 pulmonary edema) was observed in rats exposed to 100 or 200 ppm phosgene and sacrificed 0 33 and 30 minutes after exposure. However, 60 minutes post-exposure, the 100 ppm exposure 34 group had a 6.7% increase in lung water and the 200 ppm exposure group had an 8.7% increase 35 in lung water. Cytochrome C oxidase activities (specific and total) from the lungs were 36 decreased, ranging from 30.1 to 79.8% after rats were exposed to 100 ppm and sacrificed 0, 30, 37 and 60 minutes after exposure. After exposure to 200 ppm, relative serum lactic dehydrogenase 38 (LDH) concentrations were increased from one to three fold over the postexposure time of 0 to 39 90 minutes. An exposure to 430 ppm resulted in decreased lung LDH activities (specific and 40 total) ranging from 3.3 to 70.8% in the organelle fractions (homogenate and soluble). The 41 authors suggested that the decreased LDH activities were indicative of cellular damage resulting 42
in increased serum LDH concentrations. 43

44 In a different report, Pawlowski a nd Frosolono (1977) describe pulmonary 45 ultrastructural alterations in male CFE Carworth rats exposed to phosgene in a manner 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 28 of 73

essentially identical to that described in Fr osolono and Pawlowski (1977). Immediately after 1 exposure, animals exposed to 100 ppm phosgene exhibited vesiculation of ciliated and Clara 2 cell cytoplasm in the bronchiolar epithelium, while interstitial edema was observed 30 minutes 3 post-exposure. In animals exposed to 200 ppm phosgene, interstitial edema was observed 4 immediately after exposure, while focal Type I cell discontinuities and interstitial and 5 intracellular edema were present 30 minutes post-exposure. At 48 minutes post-exposure to 6 200 ppm phosgene, interstitial cellular edema with general septal thickening and involvement of 7 type II cells was observed. At 430 ppm, cytoplasmic sequestration figures were observed in 8 Type II cells 60 minutes post-exposure. 9

10 In another study, lavage protein concentrati ons and histopathological assessments of the 11 lungs were determined in male Wistar rats (10-15/group) exposed to 0, 0.1, 0.15, 1, 2.5, or 12 5 ppm phosgene for 10, 20, 50, 60, 250, 330, or 500 minutes (Diller et al., 1985). The exposure 13 concentrations and durations were paired so as to provide different exposure scenarios corres14 ponding to  50 ppm-min. A special 7 L plexiglass chamber was constructed to achieve reliable 15 exposures to low concentrations of phosgene. Air exchange was 8-fold/minute and consistency 16 of phosgene concentration throughout the chamber was confirmed by a movable suction probe. 17 Long-term mean phosgene concentrations were measured by collection of the gas samples in a 18 glass bubbler and subsequent titration. Consistency throughout exposure was determined by a 19 galvanometric analyzer, and concentration was checked using detector paper. Animals were 20 sacrificed either 24 or 48 hours after the phosge ne exposure. A phosgene concentration of 50 21 ppm-min (5 ppm for 10 min) was required to produce alveolar edema. A concentration of 50 22 ppm-min was also required to produce an increase in LFP, while widening of pulmonary 23 interstices was observed at 25 ppm-min. No phosgene threshold was observed for the latter two 24 parameters down to 0.1 ppm, indicating that the CT= k relationship is valid for these two 25 parameters. However, under the conditions of this study, Haber = s rule appears to be valid for 26 pulmonary edema only down to 5 ppm phosgene. 27

28 Franch and Hatch (1986) exposed male Sprague-Dawley rats to either 1 ppm phosgene 29 for four hours with the sacrifices occurring i mmediately after exposure and on recovery period 30 days 1, 2, 7, or 14 or 1 ppm of phosgene for seven hours with the sacrifices occurring hourly 31 during the exposure period. The exposure system and parameters are similar to those described 32 in Section 3.2.1 (Hatch et al., 1986). Actual chamber concentrations were 0.98  0.03 ppm for 33 the 4 hour exposure regimen and 1.03  0.02 ppm for the 7 hour exposure regimen. Body 34 weights of rats exposed to 1 ppm phosgene for 4 hours were significantly (p  0.01) decreased to 35 13% below controls on day 1 post-exposure. Body weights increased toward control values, 36 achieving 3% below controls on day 14. Food consumption was also decreased compared to 37 controls but was less than 10% below normal by day 4. Lung weights of exposed animals were 38 60% greater than controls immediately after exposure and remained elevated through day 7 39 post-exposure. Lung nonprotein sulfhydryl (NPSH) was similar in control and exposed rats on 40 day 1, had increased to 80% above controls on day 2, and decreased back to control levels by 41 day 7. Glucose-6-phosphate dehydrogenase (G6PD) activity was increased 40% in exposed 42 animals compared to controls from days 1 through 14. Sequential examination every hour 43 during a 7 hour exposure revealed lung weights in creasing 4 hours into the exposure, reaching a 44
maximum elevation of 60% above controls at 6 hours. Both the NPSH and G6PD activities 45 were decreased in this exposure regimen. 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 29 of 73

1 Frosolono and Currie (1985) investigated the effect of phosgene on the pulmonary 2 surfactant system (PSS) in groups of 6-14 rats exposed to 1 ppm phosgene for 4 hours. The 3 exposure system and parameters are similar to those described in Section 3.2.1 (Hatch et al., 4 1986). The actual chamber concentration was 1.0  0.06 ppm. Animals were sacrificed 5 immediately after exposure, or on postexposure Days 1, 2, or 3. Pulmonary edema was present 6 immediately after exposure and persisted through day 3. Phosphatidylinositol was significantly 7 (p<0.05) decreased compared to controls immediately after exposure only. Phosphatidylserine 8 and phosphatidylethanolamine were significantly increased compared to controls on days 1,2, 9 and 3 post-exposure. Phosphatidylcholine was increased at all time points compared to 10
controls. 11

12 Jaskot et al. (1989) exposed groups of male Sprague-Dawley rats (16/group) to 0 or 0.5 13 ppm phosgene for 4 hours. The exposure system and parameters are similar to those described 14 in Section 3.2.1 (Hatch et al., 1986). The actual chamber concentration was 0.54  0.05 ppm. 15 The rats were sacrificed immediately or 24 hours post-exposure. Phosgene exposed rats 16 showed no changes in angiotensin-converting enzyme (ACE) activity in lavage fluid or serum 17 compared to controls. Whole-lung ACE activity was significantly increased immediately after 18 exposure and 24 hours post-exposure, with increases of 55% and 44% above controls, 19 respectively. Phosgene exposed rats also had increased ACE activity in lavage cell pellets, with 20 increases of 50% and 54% above controls at 0 and 24 hours, respectively. 21

22 Assessment of pulmonary immunocompetence was determined by exposing male Fisher 23 344 rats to 0.1, 0.5, or 1 ppm phosgene for 4 hours and measuring pulmonary natural killer cell 24 activity on Day 1, 2, 4, or 7 post-exposure (Burleson and Keyes, 1989). The animals were 25 exposed in a Rochester chamber, with temperature and humidity maintained at 23.3  1.7 o C and 26

60  10%, respectively. The chamber atmosphere was continuously monitored during exposures 27 by both gas chromatography and infrared analysis. The actual chamber concentrations were 28 0.97, 0.49, and 0.10 ppm for the 1, 0.5, or 0.1 ppm groups, respectively. The pulmonary natural 29 killer activities in the rats exposed to 1 ppm were significantly (p<0.05) decreased on Days 1, 2, 30 and 4. A decrease (p<0.05) in natural killer cell activity was also observed in the 0.5 ppm 31 group. No effect was noted in the 0.1 ppm group. 32

33 Another immunological assessment, pulmonary cytotoxic T-lymphocyte (CTL) activity, 34 was examined in male Fischer 344 rats exposed to 0 or 1 ppm phosgene for four hours. 35 Animals were exposed in a Rochester exposure chamber, and the exposure atmosphere was 36 monitored by gas chromatography and infrared analysis. The actual exposure concentration 37

was 1.0  0.04 ppm. Twenty-four hours after phosgene exposure, subsets of both the control and 38 phosgene-treated rats were infected with influenza virus. The remaining control and phosgene39 exposed rats were sham infected with uninfected lung homogenate. Animals were sacrificed on 40 Day 2, 5, 7, 10, 15, or 20 post-infection (Ehrlich et al., 1989). 41

42 A significant suppression of CTL activity was noted in phosgene-exposed, influenza43 infected rats compared to air controls, air inf ected, and phosgene-treated sham-infected animals. 44 This effect was observed only on Day 10 post-infection; however, this is a time when peak 45 activity is normally detected in control rats. Body weights were significantly decreased 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 30 of 73

(p<0.05) in phosgene exposed-infected and uninfected rats on day 2 post-infection and in 1 phosgene-exposed, infected animals at day 5. Lung weights were significantly increased 2 (p<0.05) in phosgene exposed-infected and uninfected rats on days 2 and 5 post-infection 3 compared to air infected and air uninfected controls. 4

5 3.2.3. Guinea Pigs 6

7 Cameron et al. (1942) exposed 10 guinea pigs to an average phosgene concentration of 8 0.86 ppm for five hours. All survived an apparent 24-hour postexposure period. 9

10 Hatch et al. (1986) exposed Hartley guinea pigs (8/group) to 0, 0.1, 0.2, 0.5, or 1 ppm 11 phosgene for four hours. The exposure system and parameters are similar to those described in 12 Section 3.2.1 (Hatch et al., 1986). Actual chamber concentrations were within 2 to 6% of target 13 concentrations. Eighteen to 20 hours post-exposure, the lungs were lavaged and analyzed for 14 lavage fluid protein (LFP). The LFP findings were 305  19, 228  47, 407  75, 524  47, or 15

1212  149 (units not provided) for 0, 0.1, 0.2, 0.5, or 1 ppm, respectively. The lowest 16 exposure concentration producing a significantly (p<0.05) altered protein concentration was 0.5 17

ppm. 18

19 In another study, Hartley guinea pigs (5/group) were exposed to 0, 0.25, or 0.5 ppm 20 phosgene for 4 hours (Slade et al., 1989). The exposure chamber and atmosphere generation 21 and measurement systems were similar to those used by Hatch et al. (1986). The LFP 22 concentrations were measured 16 to 18 hours after exposure. These investigators found that the 23 LFP concentrations were elevated by 90% in animals exposed to 0.25 ppm phosgene and 250% 24 in animals exposed to 0.5 ppm phosgene, when compared to controls. 25

26 Male Hartley guinea pigs were exposed whole-body to either air or 22 ppm phosgene for 27 20 minutes and scarificed immediately post-e xposure for bronchoalveolar lavage (BAL) fluid 28 analysis (Sciuto, 1998). The BAL fluid was analyzed for total glutathione (GSH), lipid 29 peroxidation thiobarbituric acid reactive substances (TBARS) and protein. Lung edema was 30 also assessed by obtaining lung wet weight and lung wet/dry ratios. The study did not report 31 any deaths during exposure. In all three species, there was a statistically significant (p<0.001) 32 increase in protein levels in the BAL. 33

34

3.2.4. Hamsters 35

36 Hatch et al. (1986) exposed Syrian Golden hamsters (8/group) to 0, 0.1, 0.2, 0.5, or 1 37 ppm phosgene for four hours. The exposure system and parameters are similar to those 38 described in Section 3.2.1 (Hatch et al., 1986). Actual chamber concentrations were within 2 to 39 6% of target concentrations. Eighteen to 20 hours post-exposure, the lungs were lavaged and 40 analyzed for lavage fluid protei n (LFP). The LFP findings were 319  6, 347  14, 520  63, 41

1289  92, or 3035  111 (units not provided) for 0, 0.1, 0.2, 0.5, or 1 ppm, respectively. The 42 lowest exposure concentration producing a statis tically significantly (p<0.05) altered protein 43 concentration was 0.2 ppm. 44

45PHOSGENE DRAFT REVISED 1: 10/2009 Page 31 of 73

3.2.5. Rabbits 1

2 Cameron et al. (1942) exposed 10 rabbits to an average phosgene concentration of 0.86 3 ppm for five hours. All survived an apparent 24-hour postexposure period. 4

5 Hatch et al. (1986) exposed New Zealand white rabbits (8/group) to 0, 0.1, 0.2, 0.5, or 1 6 ppm phosgene for four hours. The exposure system and parameters are similar to those 7 described in Section 3.2.1 (Hatch et al., 1986). Actual chamber concentrations were within 2 to 8 6% of target concentrations. Eighteen to 20 hours post-exposure, the lungs were lavaged and 9 analyzed for lavage fluid protei n (LFP). The LFP findings were 292  11, 309  20, 346  26, 10

517  68, and 855  71 (units not provided) for 0, 0.1, 0.2, 0.5, or 1 ppm, respectively. The 11 lowest exposure concentration producing a signifi cantly (p<0.05) altered protein concentration 12 was 0.5 ppm. 13

14 3.2.6. Dogs 15

16 Young adult (6-12 month old) male and female beagle dogs were exposed for 30 17 minutes to phosgene in a head-only inhalation exposure at concentrations of 0 (5 dogs), 2.3, 4.1 18 or 8.8 ppm (4 dogs/concentration) (Pauluhn, 2006c). The sexes of the dogs exposed were as 19 follows: controls- 1 m and 4 f; 2.3 ppm- all males; 4.1 and 8.8 ppm- 2 m and 2 f. The target 20 phosgene concentrations were attained by dilution cascades prior to being distributed to the 21 directed-flow head-only chamber. The chamber had an internal volume of 11 L and was 22 operated in a well-ventilated room. The stability, homogeneity and the time to achieve steady 23 state were all continuously monitored using either an infrared process analyzer or a CM4 toxic 24 paper tape monitor and by the 2-HMP derivatization method with subsequent gas 25 chromatographic determination. Dogs were exposed while suspended in slings by placing their 26 heads into a size-adjustable exposure port. Parameters measured included respiratory minute 27 volume (pre-exposure, just after exposure and prior to sacrifice); arterial blood gas analysis 28 (pre-exposure and pre-sacrifice); bronchoalveolar lavage (BAL) (24 hrs post-exposure) and 29 necropsy and histopathology (24 hrs post-exposure). 30

31 During exposure, dogs exposed to 2.3 and 4.1 ppm displayed signs of irritation: minor 32 nasal discharge, salivation and lacrimation. The dogs in the 8.8 ppm group displayed labored 33 breathing, reddened conjunctiva/mucosa and vomitus and rales on day 1 post-exposure. 34 Measured respiratory minute volume indicated interdog variability that was higher in the mid35 and high-concentration males than the females and appeared to be a result of distress-related 36 hyperventilation. Statistically significant increases (p<0.05) in wet lung weight to body weight 37 ratio, absolute lung weight and the level of BAL protein were observed in the 8.8 ppm exposed 38 dogs. The BAL PMNs were elevated in both the 4.1 and 8.8 ppm exposed groups. Alveolar gas 39 exchange was impaired slightly in the highest concentration dogs as evidenced by decreased 40 arterial pO 2 . At necropsy, 3/4 dogs exposed to 8.8 ppm had pulmonary fibrinous inflammation, 41 epithelial necrosis, hemorrhages, intra-alveolar fibrin exudation, minimal to slight focal septal 42 thickening and positive Sirius-red reaction. Lung edema was also observed in these dogs. 43

44 Coman et al. (1947) exposed adult mongrel dogs to 108-197 ppm phosgene for 30 45 minutes and sacrificed the animals from 0.63 to 8.58 hours after exposure or to 71-80 ppm 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 32 of 73

phosgene for 3 minutes and sacrificed the animals from 0.13 to 5.32 hours after exposure. Mild 1 to severe emphysema was observed in all dogs, with severity generally correlating to exposure 2 concentration and time. Swelling and sloughing of the bronchiolar mucosa were then observed 3 and were usually confined to bronchioles proxi mal to the respiratory bronchioles. Transient 4 bronchiolar constriction, followed by dilatati on of the bronchioles, was also observed. 5 Congestion of the lung and alveolar edema usually followed in the lower exposure 6 concentrations at the 30-minute exposure time with the lung congestion preceding alveolar 7 edema in the higher exposure concentrations at the three-minute exposure time. Lung/body 8 weight ratios increased as both exposure concentration and/or sacrifice time after exposure 9
increased. 10

11 In another study, adult mongrel dogs were exposed to phosgene concentrations that 12 fluctuated between 24 and 40 ppm for 30 minutes (Clay and Rossing, 1964). The experimental 13 design was as follows: (1) two dogs served as controls, (2) seven dogs were exposed one or two 14 times and sacrificed one or two days after the last exposure, (3) seven dogs were exposed four 15 to 10 times and sacrificed from one to seven days after the last exposure, (4) five dogs were 16 exposed 15 to 25 times and sacrificed immediately and from 1 to 14 days after the last exposure, 17 and (5) four dogs were exposed 30 to 40 times and sacrificed immediately or from 1 to 12 18 weeks after the last exposure. For all animals exposed one or two times, acute bronchiolitis or 19 peribronchiolitis developed. Pulmonary emphysema was produced in dogs receiving more than 20
two exposures. 21

22 3.2.7. Sheep 23

24 Groups of ten unanesthetized, adult sheep were exposed to 0 or 767 ppm phosgene for 25 10 minutes (Assaad et al., 1990). Blood samples were collected immediately before the 26 exposure and 15, 30, 60, 120, 180, or 240 minutes after the exposure; and plasma prostacyclin 27 and thromboxane metabolites (6-keto-PGFl

a and TXB 2 ) concentrations were measured. Levels 28 of both metabolites were significantly (p<0.05) increased in the exposed animals compared to 29 pre-exposure baseline values and air control values. The 6-keto-PGFl

a returned to control 30 values by 180 minutes, whereas the TXB 2 did not. The authors concluded that (1) acute lung 31 injury occurred immediately following exposure even though pulmonary edema and symptoms 32 of pulmonary toxicity developed 4 to 8 hours after exposure, (2) phosgene may induce 33 pulmonary edema by injuring cell membranes, and (3) arachidonic acid metabolites may be 34 useful as early, non-specific markers for phosgene-induced lung injury. 35

36 In a subsequent study (Assaad et al., 1991), 10 unanesthetized adult sheep were exposed 37 to 0 or 767 ppm phosgene for 10 minutes and were sacrificed four hours post-exposure. Gross 38 examination of the lungs revealed congestion and edema, while the light microscopic evaluation 39 demonstrated alveolar and interstitial edema, fibrin and neutrophil exudation in the air spaces, 40 and increased alveolar macrophages. The electron microscopic examination revealed that Type 41 I pneumocytes had intracellular swelling, necrosis, and denuding of basement membrane with 42 the preservation of the tight junctions. Type II pneumocytes showed loss of lamellar bodies, 43 cytoplasmic swelling, and damage to the endoplasmic reticulum. Endothelial cells showed 44 increased density and vesicular activity, cytoplasmic swelling, and displacement of the 45
basement membrane. 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 33 of 73

1 Five Dorset-crossbred wether sheep underwent surgery in order to provide simultaneous 2 information concerning phosgene exposure and pulmonary vascular and interstitial fluid 3 dynamics (Keeler et al., 1990a). The efferent duct of the caudal mediastinal lymph node was 4 cannulated to monitor pulmonary lymph flow. Additionally, a carotid arterial catheter, a 5 pulmonary artery catheter, and a left atrial catether were implanted to monitor systemic and 6 pulmonary hemodynamics. After a 5- to 7-day recovery period, the sheep were exposed to 7 480-600 ppm phosgene for 10 minutes. The control pulmonary lymph flow rate was 10.3  2.2 8 g/hour, and the exposed sheep values were 19.5  6.0, 21.5  6.0, 22.5  6.0, 24.0  5.9, 26.5  5.3, 9

26.9  6.0, or 27.3  5.8 g/hour for 1, 1.5, 2, 2.5, 3, 3.5, or 4 hours post-exposure, respectively. 10 There was a small increase in mean pulmonary microvascular pressure, but no change in the 11 ratio of lymph to plasma protein concentration. Sheep were sacrificed four hours after 12 exposure. Histopathological evaluations of the lungs revealed diffuse, moderate alveolar and 13
interlobular edema. 14

15
3.2.8. Goats 16

17 Cameron et al. (1942) exposed two goats to an average phosgene concentration of 0.86 18 ppm for five hours. Both survived an apparent 24-hour postexposure period. 19

20
3.2.9. Cats 21

22 Cameron et al. (1942) exposed two cats to an average phosgene concentration of 0.86 23 ppm for five hours. One cat became A very ill @ with considerable labored breathing, but both 24 survived an apparent 24-hour postexposure period. 25

26 3.2.10. Monkeys 27

28 Cameron et al. (1942) exposed two monkeys to an average phosgene concentration of 29 0.86 ppm for five hours. One of the monkeys became A very ill @ with considerable labored 30 breathing, but both survived an apparent 24-hour postexposure period. 31

32 3.3. Repeated Exposure Studies 33

34 Franch and Hatch (1986) exposed male Sprague-Dawley rats (10 weeks old) to 0.125 or 35 0.25 ppm phosgene, 4 hours/day, 5 days/week for a total of 17 days; rats were sacrificed on 36 days 3, 7, 10, 13, 17 and after a 2 or 20 day recovery period. Animals were exposed in 0.32 m 3 37 Rochester-type chambers while in individual wire-mesh cages. Chamber air was measured 38 every 10-minutes and analyzed with a gas chromatograph. Lungs from exposed rats were 39 weighed and then prepared for histopathology or biochemical assays. No changes in body 40 weight were observed in any treated rats. In the 0.25 ppm group, lung wet weight was 41 approximately 25% greater than controls (p ≤ 0.01) on day 7 but was similar to control by day 2 42 of recovery. An increase in NPSH content and G6PD activity was noted in the 0.25 ppm group. 43 All values were similar to controls by day 2 post-exposure. Hydroxyproline content was not 44 affected by exposure. Lung lesions in the 0.125 ppm rats were only described as “minimal” on 45 histopathologic examination after 17 days of expos ure; lungs of the 0.25 ppm rats had moderate 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 34 of 73

multifocal mononuclear-cell accumulation in the walls of the terminal bronchioles and alveoli. 1 Some alveolar cell hyperplasia and macrophages were also observed. 2

3 Male Fischer 344 rats (60 days old) were exposed to either clean air (controls; n=12) or 4 to phosgene (n=8/concentration) gas 6 hrs/day at concentrations of 0.1 ppm (5 days/week), 0.2 5 ppm (5 days/week), 0.5 ppm (2 days/week) or 1.0 ppm (1 day/week) for 4 or 12 weeks 6 (Kodavanti et al.,1997). One group of rats at each exposure concentration was allowed clean air 7 recovery for 4 additional weeks after the 12 week exposure. Rats were exposed whole-body in 8 either Hazelton 2000 chambers (0, 0.1, 0.2 or 0.5 ppm) or Rochester chambers (0 and 1.0 ppm) 9 with a control group placed in each chamber; 8 controls were exposed in the Hazelton chamber 10 and 4 in the Rochester. Animals in the Hazelton chamber remained in the chamber even during 11 non-exposure times but the animals in the Rochester chamber were moved in and out from an 12 animal room; no differences were observed in any parameters between the two control groups. 13 Phosgene was controlled in the chambers using a mass-flow controller and chamber 14 concentrations were monitored from samples taken every 20 minutes using gas 15 chromatography. At the scheduled sacrifice, th e lungs were removed, weighed and the left lung 16 was used for histopathology and the right for bi ochemical analysis. Biochemical analysis 17 included hydroxyproline and prolyl hydroxylase activity to measure collagen synthesis and 18 desmosine concentration to measure an index of elastin in the lungs. No mortality was reported 19 at any exposure level. A small but significant decrease in mean body weight (p<0.05) was 20 observed in the 0.5 and 1.0 ppm rats at 4 and 12 weeks. A concentration-dependent increase in 21 the mean lung to body weight ratio was seen following both 4 and 12 weeks of exposure 22 (statistically significant at 0.2 ppm or greater). Mean lung displacement volume (used as index 23 of change in lung volume) was statistically signi ficantly increased in a concentration-dependent 24 manner beginning at 0.1 ppm at 4 weeks and at 0.2 ppm or greater at 12 weeks of exposure. 25 The mean values for the parameters measured (body weight, lung weight and lung displacement 26 volume) were provided in bar graphs; indivi dual data were not provided.Histopathological 27 examination of the lung was conducted in all groups after 4, 12 and 16 (4- week recovery) 28 weeks. In animals exposed for 4 weeks, there were changes in the bronchiolar regions, with a 29 small but apparent thickening and mild inflammation seen at 0.1 ppm that progressed in severity 30 with concentration to extensive inflammation and thickening of the terminal bronchiolar regions 31 and alveolar walls at 1 ppm, although the samples for 0.5 ppm were lost. An increase in 32 collagen indicated by trichrome staining was seen in the 0.2 and 1 ppm animals, although no 33 elevation of total hydroxyproline, a measure of collagen deposition, was observed after 4 34 weeks. Similar changes were seen following 12 weeks of exposure; the lesions did not appear to 35 have progressed beyond those seen at 4 weeks. Both pulmonary prolyl hydroxylase activity and 36 pulmonary desmosine were elevated at 4 and 12 weeks of exposure in the 1.0 ppm animals. The 37 intensity of collagen staining in the bronchiolar region was increased, compared to controls, in 38 the 0.2 and 1 ppm groups. The pulmonary hydroxyproline level was significantly elevated only 39 in the 1 ppm animals after 12 weeks of exposure. 40

41 Only the 1.0 ppm rats had a small but significant increase in lung to body weight ratio 42 and significant decrease in body weight after the 4 week recovery. Resolution of almost all 43 histopathological findings occurred after the 4 w eek recovery. Prolyl hydrolase activity and 44 desmosine concentration returned to normal with recovery, but hydroxyproline activity was still 45 statistically significantly increased in the 0.5 and 1.0 ppm rats. Collagen staining remained at 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 35 of 73

the same level of intensity as seen in the 12-week groups dosed at 0.2 and 1 ppm. Overall, the 1 changes induced by phosgene were not amplified with 12 weeks of treatment compared to 4 2 weeks and most pulmonary alterations were reversible after a 4 week recovery. 3

4 3.4. Developmental/Reproductive Toxicity 5

6 Developmental and reproductive toxicity studies regarding animal exposure to phosgene 7
were not available. 8

9 3.5. Genotoxicity 10

11 Genotoxic studies regarding animal exposure to phosgene were not available. However, 12 the two highly reactive chlorines of phosgene suggest that it could act on DNA in a similar 13 manner to that of bifunctional alkylating agents (Shah et al., 1979). 14

15 3.6. Carcinogenicity 16

17 A study by Selgrade et al. (1989) showed that exposure to very low levels of phosgene 18 enhances the susceptibility of mice to lung tumor formation. Female C57BL/6 mice were 19 exposed for 4 h to 0.01 (N=13), 0.025 (N=28), or 0.05 ppm phosgene (N=35) and injected 20 intravenously with syngeneic B16 melanoma cells on the following day. Controls were injected 21 with tumor cells and exposed to air. The lungs were removed 2-3 weeks after tumor cell injec22 tion and the tumors were counted. Compared with controls, there was a statistically significant 23 (p<0.05) increase in the number of B16 melanoma tumors in the lungs of mice treated with 24 0.025 or 0.05 ppm phosgene. The number of tumors/lung were 105, 110, or 185 in mice treated 25 with 0.01, 0.025, or 0.05 ppm, respectively, compared with 90, 75, or 100 in the respective 26 control groups. Exposure to 0.025 ppm was considered the lowest-observed-effect level. 27 Extending the exposure time from 4 to 8 h did not alter the susceptibility to B16 tumors at 28 0.01 ppm. 29

30 In other experiments using a higher concentration, mice were exposed by inhalation to 31 0.5 ppm phosgene for 4 h and injected intravenously with melanoma tumor cells on the 32 following day or injected with tumors and then exposed to 0.5 ppm for 4 h/day for 4 33 consecutive days. There was a significant increase (p<0.05) in the number of lung tumors in the 34 group exposed to phosgene prior to inoculation (96 tumors/lung compared with 38 tumors/lung 35 for controls). Although the number of tumors in mice exposed to phosgene on 4 consecutive 36 days beginning immediately after tumor injection was higher than in controls (65 tumors/lung 37 compared with 48 tumors/lung for controls), the difference was not statistically significant. 38 These experiments showed that exposure following tumor injection had little effect on tumor 39 susceptibility compared with phosgene exposure prior to tumor injection. 40

41 3.7. Summary 42

43 Animal lethality studies are abundant; however, the studies are of varying quality and 44 many are incompletely reported. Thus, the utility of the lethality studies must be considered on 45 a case by case basis. Even though there are limitations concerning these studies, there appears 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 36 of 73

to be little species variability between rats, mice, and guinea pigs, and the CT=k relationship 1 appears to be generally valid (although at very high or very low concentrations or exposure 2
times so short that the animal can hold it = s breath, the CT=k relationship may not hold). 3

4 Many nonlethal acute inhalation studies exist, and are of generally good quality. These 5 studies also suggest that there are few differences between species after acute exposure to 6 phosgene and that the type and sequence of effects are similar in humans and experimental 7 animals. Many of the nonlethal toxicity studies describe biochemical changes in lung fluid, 8 whose pathogenesis is likely due to acylation (see Section 4.2). Selected biochemical and other 9
nonlethal effects are summarized in Table 12. 10PHOSGENEDRAFT REVISED 1: 10/2009Page 37 of 73TABLE 12. Summary of Non-Lethal AnimalInhalation Studies With PhosgeneConcentration (ppm) Time Species Effect Reference0 or 8 20 min Mouse LOAEL≥8 ppm, based on acidosis, clinicalsigns and↓body wt.,↑lung ww/dwSciuto et al., 20010 or 22 20 min Mouse, rat andguinea pigLOAEL≥22 ppm, based on↑LFP Sciuto, 19980, 2.1, 4.3 or 8.8 30 min*dogs sacrificed 24-hrpost-exposureDog LOAEL= 4.3 ppm, based on increased PMNsin BAL fluidNOAEL = 2.3 ppmPauluhn, 2006c0.2, 0.5, 1.0, 2.0 or 4.0 30 min RatLOAEL = 2.0 ppm, based on clinical signsand↓body wt.,↑LFPNOAEL = 1. 0 ppmPauluhn, 2006b2 90 min Rat Chemical pneumonia Gross et al., 19650, 0.05, 0.1, 0.2, 0.4 or 1.0 240 min Rat LOAEL = 0.2 ppm, based on based onclinical signs and↓body wt.,↑LFPNOAEL = 0.1 ppmPauluhn, 2006b0, 0.1, 0.5 or 1.0 240 min Rat LOAEL = 0.5 ppm based on decrease in NKcell activityNOAEL = 0.1 ppmBurleson and Keyes,19890 or 1.0 240 min Rat LOAEL≥1.0 ppm based on↓body wt.,↑lung wtsEhrlich et al., 19890 or 0.5 240 min Rat LOAEL≥0.5 ppm based on↑LFP and lungwts,Jaskot et al., 19890, 0.25 or 0.5 240 min Guinea pig LOAEL≥0.25 ppm based on↑LFP Slade et al., 19890.1 to 0.5 240 min mouse LOAEL = 0.15 ppm based on↑phenobarbitalinduced sleeping timesNOAEL = 0.10Illing et al., 19880, 0.125, 0.25, 0.5 or 1.0 240 min Rat LOAEL = 0.25 ppm based on↑PMNs inlavage fluidNOAEL = 0.125 ppmCurrie et al., 1987a0, 0.05, 0.125, 0.25, 0.5or 1.0 240 min Rat LOAEL≥0.05 ppm based on↓ATP in lungs Currie et al., 1987b0, 0.1, 0.2, 0.5 or 1.0 240 min rat, mouse andhamsterLOAEL = 0.2 ppm based on↑LFPNOAEL = 0.1 ppmHatch et al., 19860, 0.1, 0.2, 0.5 or 1.0 240 min rabbit and guineapigLOAEL = 0.5 ppm based on↑LFPNOAEL = 0.2 ppmHatch et al., 19860 or 1.0 240 min Rat LOAEL≥1.0 ppm based on↓body wt.,↑lung wtsFranch and Hatch,19860 or 1.0 240 min Rat LOAEL≥1.0 ppm based on↑pulmonaryedemaFrosolono and Currie,19850 or 1.0 420 min Rat LOAEL≥1.0 ppm based on↑lung wts Franch and Hatch,PHOSGENEDRAFT REVISED 1: 10/2009Page 38 of 73TABLE 12. Summary of Non-Lethal AnimalInhalation Studies With PhosgeneConcentration (ppm) Time Species Effect Reference19860.125 or 0.25 4 hrs/day, 5 days/week for17 daysRat LOAEL = 0.25 ppm based on↑lung wts and↑NPSH and G6PD activityNOAEL = 0.125 ppmFranch and Hatch,19860, 0.1, 0.2, 0.5 or 1.0 0.1 ppm for 5 days/week;0.2 ppm for 5 days/week;0.5 ppm for 2 days/week;1.0 ppm for 1 day/weekAll exposed 6 hrs/day forup to 12 weeksRat LOAEL = 0.1 ppm based on reversible lunghistopathology;↑lung displacement volumeNOAEL = noneKodavanti et al., 199712PHOSGENE DRAFT REVISED 1: 10/2009 Page 39 of 73

4. SPECIAL CONSIDERATIONS 1 4.1. Metabolism and Disposition 2

3 Following inhalation exposure, a small portion of phosgene hydrolyzes to hydrochloric 4 acid (HCl) and carbon dioxide (CO 2 ) in the mucous coating of the upper respiratory tract 5 (Diller, 6 1985), but in the moist atmosphere of the terminal spaces of the lungs more extensive hydroly7 sis is thought to occur (Beard, 1982). Although phosgene is only slightly soluble in water, once 8 in solution it rapidly hydrolyzes to HCl and CO 2 . However, phosgene reacts even faster with 9 other functional groups such as amino, hydrazino, and sulfhydril groups (Jaskot et al., 1991; 10 Diller, 1985). 11

12 4.2. Mechanism of Toxicity 13

14 The toxicity of phosgene is due to both acylation and hydrolysis. The acylation is most 15 important and results from the reaction of phosgene with nucleophiles such as amino, hydroxyl, 16 and sulfhydryl groups of macromolecules. The acylation causes lipid and protein denaturation, 17 irreversible membrane changes, and disruption of enzymatic function. Phosgene depletes lung 18 glutathione, and glutathione reductase and superoxide dismutase increase as a result of the 19 lung = s response to injury. Cellular glycolysis and oxygen uptake are decreased following 20 exposure to phosgene, and there is a decrease of intracellular ATP and cyclic AMP associated 21 with increased permeability of pulmonary vessels and pulmonary edema. Phosgene exposure 22 also causes increased lipid peroxidation and increased leukotriene synthesis, but no change in 23 cyclooxygenase metabolism (TEMIS, 1997). 24

25 The hydrogen chloride formed by the hydrolysis of phosgene causes the initial irritation 26 to the eyes, nasopharynx, and respiratory tract. However, because of phosgene = s poor water 27 solubility, only a minimal amount of hydrogen chloride is formed (TEMIS, 1997). 28

29 4.3. Structure-Activity Relationships 30

31 Phosgene is a reactive intermediate of both chloroform and carbon tetrachloride 32 metabolism. Chloroform is metabolized by oxidative dehydrochlorination of its carbon33 hydrogen bond to form the highly unstable trichloromethanol (Cl 3 COH) which is then 34 spontaneously converted to phosgene. This reaction is catalyzed by cytochrome P-450 and 35 occurs both in the liver and kidneys. The evidence for phosgene formation from chloroform 36 was the isolation of 2-oxothioazolidine-4-carboxy lic acid from the microsomal incubation of 37 chloroform in the presence of cysteine. This compound is the expected product of the reaction 38 of phosgene with cysteine (Pohl et al., 1977; Mansuy et al., 1977). The electrophilic phosgene 39 further reacts with water to yield CO 2 and Cl - (major end products of chloroform metabolism), 40 but significant amounts of phosgene bind covalently with proteins and lipids, or conjugate with 41 cysteine or glutathione (GSH) (U.S. EPA, 1985). 42

43 Covalent binding of phosgene with cellular macromolecules has been proposed as a 44 mechanism of chloroform-induced hepatic and renal toxicity (Pohl et al., 1980a,b) and it is 45 generally accepted that the carcinogenic activity of chloroform resides in its highly reactive 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 40 of 73

intermediate metabolites such as phosgene. Irreversible binding of reactive chloroform 1 metabolites to cellular macromolecules support several theoretical concepts as a mechanism for 2 its carcinogenicity (U.S. EPA, 1985). 3

4 Covalent macromolecular binding of phosgene may be prevented to some extent by 5 endogenous glutathione (GSH) (Sipes et al., 1977) . Phosgene reacts with two molecules of 6 GSH to form diglutathionyl dithiocarbonate (GSCOSG), a compound identified as a metabolite 7 of chloroform in rat liver microsomes and mouse kidney homogenates incubated with chloro8 form in the presence of GSH (Pohl et al., 1981; Branchflower et al., 1984). In mouse kidney 9 homogenates, GSCOSG was shown to be further metabolized by kidney α -glutamyl 10 transpeptidase to N -(2-oxothiazolidine-4-carbonyl)-glycine, which in turn is hydrolyzed, 11 possibly in the presence of cysteinyl glycinase, to 2-oxothiazolidine-4-carboxylic acid 12 (Branchflower et al., 1984). 13

14 The metabolism of carbon tetrachloride proceeds via cytochrome P-450-dependent 15 dehalogenation (Sipes et al., 1977). The first step involves cleavage of one carbon-chlorine 16 bond to yield Cl - and a trichloromethyl free radical which is then oxidized to the unstable 17 intermediate trichloromethanol, the precursor of phosgene. Hydrolytic dechlorination of 18 phosgene yields CO 2 and HCl (Shah et al., 1979). Although there are similarities in the 19 metabolism of chloroform and carbon tetrachloride, metabolic activation of chloroform 20 produces primarily phosgene, whereas the level of phosgene production from carbon 21 tetrachloride appears to be small. Pohl et al. (1981) compared the amount of phosgene (as 22 diglutathionyl dithiocarbamate) produced by the aerobic metabolism of carbon tetrachloride and 23 chloroform by liver microsomes from phenobarbital-treated rats. The results indicate that 24 phosgene production from carbon tetrachloride is only 4% of that produced from chloroform. 25 The reactive metabolites of both chloroform and carbon tetrachloride covalently bind to 26 proteins and lipids, but only minimally to DNA and nucleic acids. The failure of the reactive 27 species, e.g. phosgene, trichloromethyl free radical , and other metabolites, to significantly bind 28 to DNA has been ascribed to their short half-lives and to their lack of nuclear penetration (U.S. 29 EPA, 1985). 30

31

14 C-Phosgene given to intact rats labeled liver proteins and to a smaller extent lipids 32 (Reynolds, 1967). The pattern of labeling was different from that of 14 C-carbon tetrachloride 33
and was similar to that of 14 C-chloroform. It was also shown that 36 Cl-carbon tetrachloride 34 radioactivity was stably incorporated into liver lipid and protein, pointing to the trichloromethyl 35 radical rather than phosgene as the reactive form of carbon tetrachloride. Cessi et al. (1966) 36 reported that phosgene labeled the terminal amino groups of polypeptides in a manner similar to 37 in vivo protein labeling produced by carbon tetrach loride. However, after inhalation, phosgene 38 reacts completely with lavage fluid, lung tissue, and lung capillary blood so that it is unlikely 39 that phosgene will reach tissue beyond the lung (Diller, 1974). 40

41
4.4. Other Relevant Information 42

4.4.1. Haber **=** s Law and Time-Scaling 43

44 The concept of a A death product @ was introduced by Haber to explain the relationship 45 between the extent of exposure to phosgene and death (Haber, 1924). According to A Haber = s 46PHOSGENE DRAFT REVISED 1: 10/2009 Page 41 of 73

Law, @ the biological effect of phosgene is directly proportional to the exposure expressed as the 1 product of the atmospheric concentration (C) and the time of exposure (T) or CT = k, where k 2 can be death, pulmonary edema, or other biol ogical effects of phosgene exposure (US EPA, 3 1986). Haber = s Law has subsequently been shown by other investigators to be valid for both 4

nonlethal and lethal effects within certain limits. 5

6 For example, Rinehart (1962) and Rinehart and Hatch (1964) showed that the CT 7 product appears to be a valid way to express pulmonary irritation due to phosgene exposure in 8 rats. This is based on the finding of equal degrees of respiratory response, as measured by 9 reduction in pulmonary gas exchange capacity, from exposures to various combinations of C 10 and T that yield the same CT product. 11

12 Furthermore, rat and mouse lethality data from more recent well-conducted studies 13 ( Pauluhn, 2006a; Zwart et al.; 1990) also suggest that Haber = s Law may be valid for phosgene. 14 ten Berge et al. (1986) have shown that the concentration-exposure time relationship for many 15 irritant and systemically-acting vapors and gasses can be described by the relationship c n x t = 16
k. 17
When the 10- to 60-minute rat LC 50 data of Pauluhn (2006a) are utilized in a linear regression 18 analysis, a value of the exponent, n, of 1.15 is obtained; similarly, use of the 10- to 60-minute 19

rat LC 50 data of Zwart et al. (1990) yields an ‘n’ value of 0.93. The mouse 10- to 60-minute 20 lethality data of Zwart et al. (1990) yield a value of 1.3 for the exponent, n. Thus, the fact that 21 these emperically-derived values of the exponent n approximate 1, is further support that 22
Haber = s Law is valid for phosgene. 23

24 However, the validity of Haber’s Law for derivation of AEGL values is complicated by 25 the fact that high concentrations of phosgene stim ulate protective reflexes in rodents; whereas, 26 similar changes do not occur in humans and larger animals (dog) (Pauluhn, 2006c). Thus, it 27 may be difficult to extrapolate to humans from high phosgene exposure concentrations of short 28 duration in rodents. Rats exhibited a transient decrease in respiration during the first 10-15 29 minutes of exposure, leading to a decreased inhaled concentration of phosgene (Pauluhn, 30 2006a). Thus, the c x t products noted at short duration and high concentration may be higher 31 than those obtained at longer exposure durations, suggesting an apparent lower toxicity at the 32 short-duration x high-concentration exposures. Thus, for purposes of AEGL value derivation 33 from rodent data, it is more appropriate to utilize rodent studies of at least 30-minutes so that a 34 stable breathing pattern has been achieved (Pauluhn, 2006a). 35

36 4.4.2. Species Variability 37

38 An increase BAL fluid protein is a sensitive marker of phosgene-induced 39 noncardiogenic pulmonary high-permeability edema following acute inhalation exposure 40 (Pauluhn et al., 2007). In rats, c x t products of between 48 ppm·min and 60 ppm·min induced 41 increased protein in BAL fluid. [Exposures were 2.0 ppm for 30 min (Pauluhn, 2006b), or 0.2 42 ppm for 240 min (Pauluhn, 2006b; Hatch et al., 1986)], and no increase was noted from 24-30 43 ppm·min [Exposures were 0.1 ppm for 240 min or 1 ppm for 30 min (Pauluhn, 2006b)] . 44

45PHOSGENE DRAFT REVISED 1: 10/2009 Page 42 of 73

In mice and hamsters, a c x t product of 48 ppm·min induced an increase of protein in 1 BAL fluid. [Exposure was 0.2 ppm for 240 min (Hatch et al., 1986)], and no increase was noted 2 at 24 ppm·min. [Exposure was 0.1 ppm for 240 min (Hatch et al., 1986)]. 3

4 However, in dogs, a c x t product of 129 ppm·min was necessary to cause an increase in 5 protein in BAL fluid. [Exposure was 4.3 ppm for 30 min (Pauluhn, 2006c)], and no increase 6 was observed at 63 ppm·min (Pauluhn, 2006c). Thus, the CT product required to induce an 7 increase in protein in BAL fluid in dogs is approxi mately two-fold greater than in rodents, and 8 the NOAEL for increased BAL protein in dogs (63 ppm·min) is higher than the LOAEL values 9 in rodents (48-60 ppm·min). Additionally, with regard physiology of the respiratory tract and 10 acinar structure of the lung, dogs are more similar to humans than rodents (Pauluhn, 2006a, 11 2006b, 2006c; Pauluhn et al., 2007). 12

13 Therefore, these data, summarized in Table 13, suggest that an interspecies uncertainty 14 factor of no more than 1 is justified when extrapolating from laboratory animals to humans. 15

16 17
TABLE 13. Mean BAL Protein Values for Various Species Species BAL Protein CT NOAEL (ppm· min) BAL Protein CT LOAEL (ppm· min) BAL Study Quality (Reference) Mouse 24 ( 0.1 x 240) 48 (0.2 x 240) Well-conducted study, analytical methods (Hatch et al., 1986) Rat 24 (0.1 x 240) 30 (1 x 30) 48 (0.2 x 240) 60 (2 x 30) GLP Study (Pauluhn, 2006b) Hamster 24 (0.1 x 240) 48 (0.2 x 240) Well-conducted study, analytical methods (Hatch et al., 1986) Dog 63 (2.1 x 30) 129 (4.3 x 30) GLP Study (Pauluhn, 2006c) 18
19

5. RATIONALE AND PROPOSED AEGL-1 20
5.1. Human Data Relevant to AEGL-1 21

22 No human data were relevant for establishing AEGL-1 values. 23

24
5.2. Animal Data Relevant to AEGL-1 25

26 No animal data were relevant for establishing AEGL-1 values. 27

28
5.3. Derivation of AEGL-1 29

30 Appropriate data were not available for derivation of AEGL-1 values for phosgene. 31 Odor cannot be used as a warning for potential exposure. The odor threshold is reported to be 32 between 0.5 to 1.5 ppm, a value above or approaching AEGL-2 and AEGL-3 values, and 33 tolerance to the pleasant odor of phosgene occurs rapidly. Furthermore, following odor 34 detection and minor irritation, serious effects may occur after a clinical latency period of  24 35 hours. Therefore, AEGL-1 values are not recommended (Table 14). 36PHOSGENE DRAFT REVISED 1: 10/2009 Page 43 of 73

1

TABLE 14. AEGL-1 Values for Phosgene

Classification 10-min 30-min 1-hr 4-hr 8-hr

AEGL-1 NR NR NR NR NR

NR: Not Recommended. Absence of AEGL-1 values doe s not imply that exposure to concentrations below

AEGL-2 are without effect

. 2

3
6. RATIONALE AND PROPOSED AEGL-2 4
6.1. Human Data Relevant to AEGL-2 5

6 No human data were relevant to establishing the AEGL-2 values. 7

8
6.2. Animal Data Relevant to AEGL-2 9

10 Biochemical markers of phosgene exposure such as increased protein in BAL fluid were 11 observed in rats exposed to ≥ 2 ppm for 30 minutes or ≥ 0.2 ppm for 4 hours (Pauluhn, 2006b). 12 BAL protein levels were similar to those of c ontrols by 7-days post-exposure. Increased LFP 13 was also observed in mice, rats, guinea pigs, hamsters, and rabbits exposed to up to 1 ppm 14 phosgene for 4 hours (Hatch et al., 1986; Diller et al., 1985). Increased PMN counts in BAL 15 fluid were observed in dogs exposed to ≥ 4.3 ppm for 30 minutes; no effect was noted in dogs 16 exposed to 2.3 ppm for 30 minutes (Pauluhn, 2006c). Chemical pneumonia was observed in 17 rats exposed to 2.0 ppm phosgene for 90 minutes (Gross et al., 1965). Other effects defined by 18
AEGL-2 included A very ill @ monkeys with labored breathing (Cameron et al., 1942) and acute 19 bronchiolitis or peribroncholitis in dogs (Clay and Rossing, 1964). However, a lack of 20 experimental details in these monkey and dog studies renders them inappropriate for AEGL 21
derivation. 22

23
6.3. Derivation of AEGL-2 24

25 The NOAEL for increased PMNs in BAL fluid observed in dogs (2.3 ppm for 30 26 minutes) (Pauluhn, 2006c) will be used as the basis for deriving AEGL-2 values. The dog was 27 chosen over rodents because, with regard physiology of the respiratory tract and acinar structure 28 of the lung, dogs are more similar to humans than rodents. This endpoint was chosen because 29 BAL fluid changes are a sensitive marker of phosgene-induced noncardiogenic pulmonary high30 permeability edema following acute inhalation exposure (Pauluhn et al., 2007). 31

32 An uncertainty factor of 1 will be applied for interspecies extrapolation. In rats, c x t 33 products of between 48 ppm·min and 60 ppm·min induced increased protein in BAL fluid , and 34 no increase was noted from 24-30 ppm·min. In mice and hamsters, a c x t product of 48 35 ppm·min induced an increase of protein in BAL fluid, and no increase was noted at 24 ppm·min. 36 However, in dogs, a c x t product of 129 ppm·min was necessary to cause an increase in protein 37 in BAL fluid, and no increase was observed at 63 ppm·min. Thus, the CT product required to 38 induce an increase in protein in BAL fluid in dogs is approximately two-fold greater than in 39 rodents, and the NOAEL for increased BAL protein in dogs (63 ppm·min) is higher than the 40 LOAEL values in rodents (48-60 ppm·min). Additionally, with regard physiology of the 41PHOSGENE DRAFT REVISED 1: 10/2009 Page 44 of 73

respiratory tract and acinar structure of the lung, dogs are more similar to humans than rodents 1 (Pauluhn, 2006a, 2006b, 2006c; Pauluhn et al., 2007). Collectively, these data suggest that an 2 interspecies uncertainty factor of no more than 1 is justified when extrapolating from laboratory 3
animals to humans. 4

5 An uncertainty factor of 3 will be applied to account for sensitive human 6 subpopulations. The intraspecies UF of 3 is considered sufficient due to the steep 7 concentration-response curve (death in 2/10 rats exposed to 52.3 ppm and 6/10 exposed to 61.9 8 ppm for 10 min; 4/10 exposed to 13.4 ppm and 10/10 exposed to 16.7 ppm for 30-min; 4/10 9 exposed to 7.4 ppm and 10/10 exposed to 11.8 ppm for 1-hr; Pauluhn, 2006a) which implies 10 limited intra-individual variability. Also, the mechanism of phosgene toxicity (binding to 11 macromolecules and irritation) is not expected to vary greatly between individuals. The 12 concentration-time relationship for many irritant and systemically-acting vapors and gases may 13 be described by c n x t = k, where the exponent, n, ranges from 0.8 to 3.5 (ten Berge et al., 1986). 14
Haber = s Law c x t = k; n=1 has been shown to be valid for phosgene within certain limits and 15 will be used for scaling of the AEGL values. The AEGL-2 values for phosgene are presented in 16 Table 15, and the calculations for these AEGL-2 values are presented in Appendix A. 17

18

TABLE 15. AEGL-2 Values for Phosgene

Classification 10-min 30-min 1-hr 4-hr 8-hr

AEGL-2 2.3 ppm (9.5 mg/m 3 ) 0.77 ppm (3.2 mg/m 3 ) 0.38 ppm (1.6 mg/m 3 ) 0.096 ppm (0.39 mg/m 3 ) 0.048 ppm (0.19 mg/m 3 )
19
20 The AEGL-2 values are considered protective. No significant treatment-related effects 21 were noted in rats exposed to 0.125 ppm phosgene 4 hours/day, 5 days/week for 17 weeks 22 (Franch and Hatch, 1986). 23

24
7. RATIONALE AND PROPOSED AEGL-3 25
7.1. Human Data Relevant to AEGL-3 26

27 No human data were relevant to establishing the AEGL-3 values. 28

29
7.2. Animal Data Relevant to AEGL-3 30

31 Many lethality data exist in a variety of species (mouse, rat, guinea pig, rabbit, cat, dog, 32 goat, sheep, and monkeys). However, in most cases, experimental parameters are poorly 33 described and the quality of data are questionable for AEGL derivation. The mouse and rat 34

LC 50 studies of Zwart et al. (1990) ant rat studi es of Pauluhn (2006a) are the exception and are 35 appropriate for AEGL-3 derivation. 36

37
7.3. Derivation of AEGL-3 38

39 The AEGL-3 values will be based on an estimated 1-hour lethality threshold (BMCL 05 ) 40 in rats from the Pauluhn (2006a) study (3.9 ppm). The Pauluhn (2006a) study is selected over 41PHOSGENE DRAFT REVISED 1: 10/2009 Page 45 of 73

the Zwart et al. (1990) study because it utilized a nose-only protocol; whereas, Zwart utilized a 1 whole-body protocol. An uncertainty factor of 1 will be applied for interspecies extrapolation. 2

3 An increase BAL fluid protein is a sensitive marker of phosgene-induced 4 noncardiogenic pulmonary high-permeability edema following acute inhalation exposure 5 (Pauluhn et al., 2007). In rats, c x t products of between 48 ppm·min and 60 ppm·min induced 6 increased protein in BAL fluid , and no increase was noted from 24-30 ppm·min. In mice and 7 hamsters, a c x t product of 48 ppm·min induced an increase of protein in BAL fluid, and no 8 increase was noted at 24 ppm·min. However, in dogs, a c x t product of 129 ppm·min was 9 necessary to cause an increase in protein in BAL fluid, and no increase was observed at 63 10 ppm·min. Thus, the CT product required to induce an increase in protein in BAL fluid in dogs 11 is approximately two-fold greater than in rode nts, and the NOAEL for increased BAL protein in 12 dogs (63 ppm·min) is higher than the LOAEL values in rodents (48-60 ppm·min). 13 Additionally, with regard physiology of the respiratory tract and acinar structure of the lung, 14 dogs are more similar to humans than rodents (Pauluhn, 2006a, 2006b, 2006c; Pauluhn et al., 15 2007). Collectively, these data suggest that an interspecies uncertainty factor of no more than 1 16 is justified when extrapolating from laboratory animals to humans. 17

18 An uncertainty factor of 3 will be applied to account for sensitive human 19 subpopulations. The intraspecies UF of 3 is considered sufficient due to the steep 20 concentration-response curve (death in 2/10 rats exposed to 52.3 ppm and 6/10 exposed to 61.9 21 ppm for 10 min; 4/10 exposed to 13.4 ppm and 10/10 exposed to 16.7 ppm for 30-min; 4/10 22 exposed to 7.4 ppm and 10/10 exposed to 11.8 ppm for 1-hr; Pauluhn, 2006a) which implies 23 limited intra-individual variability. Also, the mechanism of phosgene toxicity (binding to 24 macromolecules and irritation) is not expected to vary greatly between individuals. The 25 concentration-time relationship for many irritant and systemically-acting vapors and gases may 26 be described by c n x t = k, where the exponent, n, ranges from 0.8 to 3.5 (ten Berge et al., 1986). 27
Haber = s Law c x t = k; n=1 has been shown to be valid for phosgene within certain limits and 28 will be used for scaling of the AEGL values for phosgene. The AEGL-3 values for phosgene 29 are presented in Table 16, and the calculations for these AEGL-3 values are presented in 30 Appendix A. 31

32

TABLE 16. AEGL-3 Values for Phosgene

Classification 10-min 30-min 1-hr 4-hr 8-hr

AEGL-3 7.8 ppm (32 mg/m 3 ) 2.6 ppm (11 mg/m 3 ) 1.3 ppm (5.3 mg/m 3 ) 0.33 ppm (1.4 mg/m 3 ) 0.16 ppm (0.66 mg/m 3 )
33
34 The AEGL-3 values may be considered protective. No deaths were noted in 35 approximately 200 workers exposed to phosgene concentrations ranging from 50 to 300 36 ppm·min (Kaerkes, 1992), and calculated AEGL-3 values are approximately 79 ppm·min. 37 Furthermore, no deaths were noted in rats exposed to phosgene 6 hrs/day at concentrations of 38 0.1 ppm (5 days/week), 0.2 ppm (5 days/week), 0.5 ppm (2 days/week) or 1.0 ppm (1 day/week) 39 for 4 or 12 weeks (Kodavanti et al.,1997). 40

41PHOSGENE DRAFT REVISED 1: 10/2009 Page 46 of 73

8. SUMMARY OF PROPOSED AEGLS 1 8.1. AEGL Values and Toxicity Endpoints 2

3 The derived AEGL values for various levels of effects and durations of exposure are 4 summarized in Table 17. Data were insufficient for deriving AEGL-1 values. Increased BAL 5 fluid protein in rats was used as the basis for AEGL-2, and estimated lethality thresholds in rats 6 (BMCL 05 ) were used for AEGL-3. 7

8

TABLE 17. Summary of AEGL Values for Phosgene

Classification 10-min 30-min 1-hr 4-hr 8-hr

AEGL-1 (Nondisabling) NR NR NR NR NR

AEGL-2 (Disabling) 2.3 ppm (9.5 mg/m 3 ) 0.77 ppm (3.2 mg/m 3 ) 0.38 ppm (1.6 mg/m 3 ) 0.096 ppm (0.39 mg/m 3 ) 0.048 ppm (0.19 mg/m 3 )

AEGL-3 (Lethal) 7.8 ppm (32 mg/m 3 ) 2.6 ppm (11 mg/m 3 ) 1.3 ppm (5.3 mg/m 3 ) 0.33 ppm (1.4 mg/m 3 ) 0.16 ppm (0.66 mg/m 3 )

NR: Not Recommended. Absence of AEGL-1 values doe s not imply that exposure to concentrations below
AEGL-2 are without effect.
9 8.2. Comparison with Other Standards and Guidelines 10

11

TABLE 18. Extant Standards and Guidelines for Phosgene
Exposure Duration Guideline 10 min 30 min 1 hr 4 hr 8 hr

AEGL-1 NR NR NR NR NR AEGL-2 2.3 ppm 0.77 ppm 0.38 ppm 0.096 ppm 0.048 ppm AEGL-3 7.8 ppm 2.6 ppm 1.3 ppm 0.33 ppm 0.16 ppm

ERPG-1 a NA

ERPG-2 a 0.5 ppm

ERPG-3 a 1.5 ppm EEGL (NRC) b
0.2 ppm 0.02 ppm (24-hr)

NIOSH IDLH c 2 ppm

NIOSH STEL d 0.2 ppm (15-min ceiling)

NIOSH REL d 0.1 ppm (10-hr)

OSHA PELTWA e 0.1 ppm

ACGIH TLV f 0.1 ppm MAK (Germany) g 0.1 ppm

MAC (Netherlands) h 0.02 ppm

a ERPG (Emergency Response Planning Guide lines, American Industrial Hygiene Association (AIHA 2009 ) 12

The ERPG-1 is the maximum airborne concentration belo w which it is believed nearly all individuals could be 13 exposed for up to one hour without experiencing other than mild, transient adverse health effects or 14 without perceiving a clearly defined objectionable odor . The ERPG-1 for Phosgene is not derived. 15 16

The ERPG-2 is the maximum airborne concentration belo w which it is believed nearly all individuals could be 17 exposed for up to one hour without experiencing or deve loping irreversible or other serious health effects 18 or symptoms that could impair an individual = s ability to take protective action. The ERPG-2 for Phosgene 19 is based on increased protein in BAL fluid from time-adjusted dog studies

. 20PHOSGENE DRAFT REVISED 1: 10/2009 Page 47 of 73

The ERPG-3 is the maximum airborne concentration belo w which it is believed nearly all individuals could be 1 exposed for up to one hour without experiencing or deve loping life-threatening health effects. The ERPG2 3 for Phosgene is based on acute animal inhalation data. 3 4

b EEGL (Emergency Exposure Guidance Le vels, National Research Council (NRC 1985) 5

The EEGL is the concentration of contaminants that can cause discomfort or other evidence of irritation or 6 intoxication in or around the workplace, but avoids d eath, other severe acute effects and long-term or 7 chronic injury. The EEGL for Phosgene is based on the A most relevant animal exposure studies (Gross et 8 al., 1965; Rinehart & Hatch, 1964) @ and studies suggesting that animals do not tolerate phosgene at 0.2 9 ppm administered 5 hr/day for 5 days (Cameron & Foss, 1941; Cameron et al., 1942). 10 11

C IDLH (Immediately Dangerous to Life and Health, Nati onal Institute of Occupational Safety and Health) 12 (NIOSH 2005 ) represents the maximum concentration from which one could escape within 30 minutes 13 without any escape-impairing symptoms, or any irrevers ible health effects. The IDLH for Phosgene is 14 based on acute inhalation toxicity data in humans. 15 16

d NIOSH REL-STEL (Recommended Exposure Limits - Short Term Exposure Limit) (NIOSH 2005 ) 17 is defined analogous to the ACGIH TLV-TWA. 18 19

e OSHA PEL-TWA (Occupational Health and Safety Ad ministration, Permissible Exposure Limits - Time 20 Weighted Average) (OSHA 1994) is defined analogous to the ACGIH-TLV-TWA, but is for exposures of 21 no more than 10 hours/day, 40 hours/week. 22 23

f ACGIH TLV-TWA (American Conference of Governmental Industrial Hygienists, Threshold Limit Value - 24 Time Weighted Average) (ACGIH 2000) is the time-weighted average concentration for a normal 8-hour 25 workday and a 40-hour workweek, to which nearly all workers may be repeatedly exposed, day after day, 26

without adverse effect. 27 28

g MAK (Maximale Argeitsplatzkonzentrat ion [Maximum Workplace Concentration]) Deutsche 29 Forschungsgemeinschaft (German Research Association) 2007 is defined analogous to the ACGIH-TLV30

TWA. 31 32

h MAC (Maximaal Aanvaaarde Concentratie [Maximal Accepted Concentration]). SDU Uitgevers (under the 33 auspices of the Ministry of Social Affairs and Em ployment), The Hague, The Netherlands 2000. is defined 34 analogous to the ACGIH-TLV-TWA. 35
36 8.3 Data Adequacy and Research Needs 37

38 No reliable, quantitative human data exist. Human data are limited to descriptive effects 39 from accidental exposure and are thus inappropriate for derivation of AEGL values. There are, 40 however, a plethora of acute inhalation data in many experimental species. The database is 41 sufficient to have good confidence in AEGL-2 and AEGL-3 values. 42

43
9. REFERENCES 44

45 ACGIH (American Conference of Governmental Indus trial Hygienists, Inc). 2000. Documentation of 46 the Threshold Limit Values and Biological Exposure Indices. 6th Edition. 47
48 AIHA (American Industrial Hygiene Association) . 2009. Emergency Response Planning Guidelines. 49 AIHA, Fairfax, VA. 50
51 Assaad, A., Trotz, M., Moore, D., Nold, J, Corcoran, K., Hurt, H., Keeler, J., Phillips, K., and Said, S.I. 52 1990. Arachidonic acid metabolites as early markers of phosgene-induced acute lung injury and 53PHOSGENE DRAFT REVISED 1: 10/2009 Page 48 of 73

pulmonary edema. World Conference on Lung Health. Boston, MA. May 20-24. Am. Rev. 1 Respir. Dis. 141: A420. 2
3 Assaad, A., Nold, J., Petrali, J., Moore, D., M itcheltree, L., Corcoran, K., and Phillips, K. 1991. 4 Pulmonary pathological alterations in sheep exposed to lethal dose of phosgene. 75 th Annual 5 Meeting of the American Societies for Experimental Biology, Atlanta, Georgia. April 21-25. 6

FASEB J. 5:A484. 7
8 Beard, R.R. 1982. Inorganic compounds of oxygen, nitrogen, and carbon. In: Patty = s Industrial 9 Hygiene and Toxicology, Vol 2C, Clayton, G.D. and Clayton, F.E., Eds. John Wiley & Sons, 10 New York. Pp. 4126-4128. 11
12 Box, G.E.P. and Cullumbine, H. 1947a. The relations hip between survival time and dosage with certain 13 toxic agents. Br. J. Pharmacol. 2:27-37. 14
15 Box, G.E.P. and Cullumbine, H. 1947b. The effect of exposure to sub-lethal doses of phosgene on the 16 subsequent L(Ct)50 for rats and mice. Brit. J. Pharmacol. 2:38-55. 17
18 Bradley, B.L. and Unger, K.M. 1982. Phosgene inhalation: A case report. Texas Med. 78:51-53. 19
20 Branchflower, R.V., Nunn, D.S., Highet, R.J., et al. 1984. Nephrotoxicity of chloroform: metabolism to 21 phosgene by the mouse kidney. Toxicol. Appl. Pharmacol. 72:159-168. 22
23 Burleson, G.R. and Keyes, L.L. 1989. Natural killer activity in Fischer 344 rat lungs as a method to 24 assess pulmonary immunocompetence: Imm unosuppression by phosgene inhalation. 25 Immunopharmacol. Immunotoxicol. 11:421-443. 26
27 Cameron, G.R. and Courtice, F.C. 1946. The produc tion and removal of oedema fluid in the lung after 28 exposure to carbonyl chloride (phosgene). J. Ph ysiol. 105:175-185. (Cited in U.S. EPA, 1986) 29
30 Cameron, G.R. and Foss, G.L. 1941. Effect of low concentrations of phosgene for 5 hours on 5 31 consecutive days in groups of different animals. Washington, DC: British Embassy Defense 32 Staff; Porton report no. 2316, serial no. 63. (Cited in U.S. EPA, 1986) 33
34 Cameron, G.R., Courtice, F.C., and Foss, G.L. 1942. Effects of exposing different animals to a low 35 concentration of phosgene 1:1,000,000 (4 mg/m 3 ) for 5 hours. (Chapter IX in First Report on 36 Phosgene Poisoning. Portion Report No. 2339.) W ashington, D.C. British Defense Staff. British 37 Embassy. (Cited in U.S. EPA, 1986) 38
39 Cessi, C., Columbini, C., and Mameli, L. 1966. Th e reaction of liver proteins with a metabolite of 40

carbon tetrachloride. Biochem. J. 101:46-47c. 41
42 Chasis, H. 1944. Phosgene: Review of Literature on the effect of exposure in man and experimental 43

animals. Contract W-49-036-CWS-1. 44
45 Clay, J.R. and Rossing, R.G. 1964. Histopathology of exposure of phosgene: An attempt to produce 46 pulmonary emphysema experimentally. Arch. Pathol. 78:544-551. 47
48 Coman, D.R., Bruner, H.D., Horn, R.C., Friedman, M., Boche, R.D., McCarthy, M.D. Gibbon, M.H., 49 and Schultz, J. 1947. Studies on experimental phosge ne poisoning: I. The pathologic anatomy of 50PHOSGENE DRAFT REVISED 1: 10/2009 Page 49 of 73

phosgene poisoning with special reference to th e early and late phases. Am. J. Pathol. 23:1037- 1

1074. 2
3 Currie, W.D., Hatch, G.E., and Frosolono, M.F. 1987a . Pulmonary alterations in rats due to acute 4 phosgene inhalation. Fundam. Appl. Toxicol. 8:107-114. 5
6 Currie, W.D., Hatch, G.E., and Frosolono, M.F. 1987b. Changes in lung ATP concentration in the rat 7 after low-level phosgene exposure. J. Biol. Toxicol. 2:105-114. 8
9 Delephine, S. 1922. Summary notes on two fatalities due to inhaling phosgene. J. Ind. Hygiene. 4:433- 10

440. 11
12 Diller, W.F. 1974. Klinik und Pathologie der phosgenvergiftung. Pneumonologie. 150:139-148. 13
14 Diller, W.F. 1978. Medical phosgene problems and th eir possible solution. J. Occup. Med. 20:189-193. 15
16 Diller, W. F., Bruch, J., and Dehnen, W. 1985. Pu lmonary changes in the rats following low phosgene 17 exposure. Arch. Toxicol. 57:184-190. 18
19 Diller, W.F. 1985. Pathogenesis of phosgene poi soning. Toxicol. Ind. Health. 1: 7-15. 20
21 Diller, W.F., Schnellbaecher, F., and Wuestefeld, E. 1979. Late pulmonary sequelae of phosgene 22 poisoning or inhalation-toxic pulmonary edema. Arbeitsmed. Arbeitsschultz Prophyl. 29: 5-16. 23 (Cited in U.S. EPA, 1986) 24
25 Diller, W.F. and Zante, R. 1982. Dosis-wi rkungs-beziehungen bei phosgen- einwirkung auf mensch und 26

tier. Zbl. Arbeitsmed. 32: 360-368 27
28 Ehrlich, J.P., Gunnison, A.F., and Burleson, G.R. 1989. Influenza virus-specific cytotoxic T-lymphocyte 29 activity in Fischer 344 rat lungs as a method to assess pulmonary immunocompetence: Effect of 30 phosgene inhalation. Inha lation Toxicol. 1:129-138. 31
32 Everett, E.D. and Overholt, E.L. 1968. Phosgene poisoning. JAMA. 205: 243-245. 33
34 Franch, S. and Hatch, G.E. 1986. Pulmonary biochemical effects of inhaled phosgene in rats. J. Toxicol. 35

Environ. Health 19:413-423. 36
37 Freeman, S., Grodins, F.S., and Kosman, A.J. 1945. The use of helium in the treatment of phosgene 38 poisoning. In: Fasciculus on chemical warfare medicine: v. II, respiratory tract. Washington, 39 DC: National Research Council, Committee on Treatment of Gas Casualities; pp. 541-550. 40 (Cited in U.S. EPA, 1986) 41
42 Frosolono, M.F. 1976. Basic Mechanism, diagnos tic procdures and therapeutic countermeasures for 43 phosgene poisoning in animals. Final re port, MCA. (Cited in U.S. EPA, 1986) 44
45 Frosolono, M.F. 1977. Basic Mechanism, diagnos tic procedures and therapeutic countermeasures for 46 phosgene poisoning in animals. Final re port, MCA. (Cited in U.S. EPA, 1986) 47
48 Frosolono, M.F. and Currie, W.D. 1985. Response of the pulmonary surfactant system to phosgene. 49

Toxicol. Ind. Health. 1: 29-35. 50
51PHOSGENE DRAFT REVISED 1: 10/2009 Page 50 of 73

Frosolono, M.F. and Pawlowski, R. 1977. Effect of phosgene on rat lungs after single high-level 1 exposure: I. Biochemical alterations. Arch. Environment Health 32: 271-277. 2
3 Frosolono, M.F. and Currie, W.D. 1985. Effect of phosgene on the pulmonary surfactant system (PSS): 4 Dose-response relationships. Biochemistry 24:3386. 5
6 Galdston, M., Leutscher, J.A., Longcope, W.T., et. al. 1947a. A study of the residual effects of 7 phosgene poisoning in human subjects: I. Afte r acute exposure. J. Clin. Invest. 26:145-168. 8
9 Galdston, M., Leutscher, J.A., Longcope, W.T., and Ba llich, N.L. 1947b. A study of the residual effects 10 of phosgene poisoning in human subjects: II. Af ter chronic exposure. J. Clin. Invest. 26:169- 11

181. 12
13 Gross, P., Rinehart, W.E., and Hatch, T. 1965. Chronic pneumonitis caused by phosgene. Arch. 14

Environ. Health. 10: 768-775. 15
16 Haber, F.R. 1924. Zur geschichte des gaskrieges [On the history of the gas war]. In: Fuenf Vortraege 17 aus den Jahren 1920-23 [Five lectures from the years 1920-1923]. Berlin, Germany: Verlag von 18 Julius Springer; pp. 76-92. (Cited in U.S. EPA, 1986) 19
20 Halpern, B.N., Cruchaud, S., Vermeil, G., and Roux, J.L. 1950. Experimental study on the pathogenesis 21 and treatment of acute pulmonary edema. Arch. Int. Pharmacodyn. Ther. 82:425-476. (Cited in 22 U.S. EPA, 1986) 23
24 Hatch, G.E., Slade, R., Stead, A.G., and Graham, J.A. 1986. Species comparison of acute inhalation 25 toxicity of ozone and phosgene. J. T oxicol. Environmental Health 19:43-53. 26
27 Hedlund, L.W., and Putman, C.E. 1985. Methods for detecting pulmonary edema. Toxicol. Ind. 28

Health. 1:59-67. 29
30 Hegler, C. 1928. On the mass poisoning by phosgene in Hamburg. I. Clinical observations. 54:1551- 31

1553. 32
33 Henschler, D. 1971. German MAK Criteria. (F rom Ehrlicher, H. 1971. Personal Communication, 34 Department of Medicine, Bayer AG, Leverkusen). 35
36 Henschler, D. and Laux, W. 1960. On the specific ity of a tolerance increase by repeated inhalation of 37 pulmonary edema-producing gases. Naunyn-Sc hmiedbergs Arch. Exp. Pathol. Pharmakol. 38 239:433-441. (Cited in U.S. EPA, 1986) 39
40 Herzog, H. And Pletscher, A. 1955. Die wirkung von industriellen reizgasen auf die 41

bronchialschleimhaut des menschen. Schweizer ische Medizinische Wochenschrift. 85:477-481. 42
43 Illing, J.W., Mole, M.L., Graham, J.A, et al. 1988. Influence of phosgene i nhalation on extrapulmonary 44

effects in mice. Inhalation Toxicol. 1:13-20. 45
46 Jaskot, R.H., Grose, E.C., and Stead, A.G. 1989. In crease in angiotensin-converting enzyme in rat lungs 47 following inhalation of phosgene. Inhalation Toxicol. 1:71-78. 48
49 Jaskot, R.H., Grose, E.C., Richards, J.H., and Doerfl er, D.L. 1991. Effects of inhaled phosgene on rat 50 lung antioxidant systems. Fund. Appl. Toxicol. 17:666-674. 51PHOSGENE DRAFT REVISED 1: 10/2009 Page 51 of 73

1 Kaerkes, B. 1992. Experiences with a phosgene indi cator badge during an eleven-year period. M.D. 2 Dissertation, Heinrich-Heine University. Duesseldorf, Germany. 3
4 Karel, L. and Weston, R.E. 1947. The biological assay of inhaled substance by the dosimetric method: 5 The retained median lethal dose and the resp iratory response in unanesthetized, normal goats 6 exposed to different concentrations of phosgene. J. Ind. Hyg. Toxicol. 29:23-28. 7
8 Kawai, M. 1973. [Inhalation toxicity of phosgene and trichloronitromet hane (chloropicrin)]. J. Sangyo 9 Igaku 15:406-407. 10
11 Keeler, J.R., Hurt, H.H., Nold, J.B., Corcoran, K.D., and Tezak-Reid, T.M. 1990a. Phosgene-induced 12 lung injury in sheep. Inhalation Toxicol. 2:391-406. 13
14 Keeler, J.R., Hurt, H.H., Nold, J.B., and Lennox, W. J. 1990b. Estimation of the LCt50 of phosgene in 15 sheep. Drug Chem Toxicol. 13:229-239. 16
17 Kimmerle, G. and Diller, W. 1977. Unveroffen tilichte Untersuchungen. (Cited in U.S. EPA, 1986) 18
19 Kirk-Othmer.. 1991. Encyclopedia of Chemical Technology. Fourth Edition. Volume 18. John Wiley 20 & Sons. New York. Phosgene. pp. 645-655. 21
22 Kodavanti, U.P., D.L. Costa, S.N. Giri, B. Starcher and G.E. Hatch. 1997. Pulmonary structural and 23

extracellular matrix alterations in Fischer 344 rats following subchronic exposure. Fundamental 24 and Applied Toxicology 37:54-63. 25
26
27 Laquer, E. and Magnus, R. 1921. Combat gas pois oning. III. Experimental pathology of phosgene 28 poisoning. Z. Gesamte Exp. Med. 13:31-107. 29
30 Leonardos, G., Kendall, D.A., and Barnard, N.J. 1968. Odor threshold dete rminations of 53 odorant 31 chemicals. Presented at the 61th Annual Meeting of the Air Pollution Control Association, St. 32 Paul, Minn., June 23-27. [Requested. NIOSH, 1976, page 29] 33
34 Lipsett, M.J., Shusterman, D.J., and Beard, R.R. 1994. Phosgene. In: Industrial hygiene and toxicology, 35 4th ed. Vol. II, part F. Clayton, G.D. and Clayton, F.E. editors, J. Wiley & Sons, Inc. pp. 4557- 36

4563. 37
38 MAC (Maximaal Aanvaaarde Concentratie [Maximal Accepted Concentration]). 2000. SDU Uitgevers 39 (under the auspices of the Ministry of Social Affairs and Employment), The Hague, The 40

Netherlands. 41
42 MAK (Maximale Argeitsplatzkonzentration [Maximum Workplace Concentration]) 2007 . Deutsche 43 Forschungsgemeinschaft (German Research Association). 44
45 Mansuy, D., Beaune, P., Crestell, T., Lange, M ., and Leroux, M. 1977. Evidence for phosgene 46 formation during liver microsomal oxidation of chloroform. Biochem. Biophys. Res. Comm. 47

79:513-517. 48
49 Meek, W.J. and Eyster, J.A.E. 1920. Experiments on the pathological physiology of acute phosgene 50 poisoning. Am. J. Physiol. 51:303-320. 51PHOSGENE DRAFT REVISED 1: 10/2009 Page 52 of 73

1 Misra, N.P., Manoria, P.C., and Saxena, K. 1985. Fa tal pulmonary oedema with phosgene poisining. J. 2 Assoc. Physicians India. 33:430-431. 3
4 Moor, S. and Gates, M. 1946. Technical repor t of division G/NDRC. (Cited in U.S. EPA, 1986) 5
6 NIOSH (National Institute of Occupational Safety and Health). 1976. Criteria for a recommended 7 standard: occupational exposur e to phosgene. NIOSH-76-137. 8
9 NIOSH (National Institute of Occ upational Safety and Health). 2005 . Phosgene. NIOSH Publication 10 2005-149. NIOSH Pocket Guide to Chemical Hazards. www.cdc.gov/niosh

. 11
12 NRC (National Research Council). 1985. Emergenc y and Continuous Exposure Limits for Selected 13 Airborne Contaminants. Phosgene. pp. 69-86. National Academy Press. Washington, D.C. 14
15 Ong, S.G. 1972. Treatment of phosgene poisoning with antiserum: anaphylac tic shock by phosgene. 16 Arch. Toxicol. 29:267-278. (Cited in U.S. EPA, 1986) 17
18 OSHA (Occupational Safety and Health Administration) . 1994. Limits for Air Contaminants. U. S. 19 Department of Labor. 29 CFR 1910.1000. 20
21 Pauluhn, J. 2006a. Acute nose-only exposure of rats to phosgene. Part I. Concentration x time 22 dependence of LC 50 s, non-lethal-threshold concentrations and analysis of breathing patterns. 23 Inhalation Toxicology 18:423-435. 24
25 Pauluhn, J. 2006b. Acute nose-only exposure of rats to phosgene. Part II. Concentration x time 26 dependence of changes in bronchoalveolar la vage during a follow-up period of 3 months. 27 Inhalation Toxicology 18:595-607. 28
29 Pauluhn, J. 2006c. Acute head-only exposure of dogs to phosgene. Part III. Comparison of indicators of 30 lung injury in dogs and rats. Inhalation Toxicology 18:609-621. 31
32 Pauluhn, J., et al. 2007. Workshop Summary: Phosgene -induced pulmonary toxicity revisited: appraisal 33 of early and late markers of pulmonary injury from animal models with emphasis on human 34 significance. Inhalation Toxicology: 19: 10, 789-810. 35
36 Patt, H.M., Tobias, J.M., Swift, M.N., Postel, S., and Gerard, R.W. 1946. Hemodynamics in pulmonary 37 irritant poisoning. Am. J. Physiol. 147:329-339. 38
39 Pawlowski, R. and Frosolono, M.F. 1977. Effect of phosgene on rat lungs after single high-level 40 exposure. II. Ultrastructural alterna tions. Arch. Environ. Health 32:278-283. 41
42 Pohl, L.R., Bhooshan, B., Whittaker, N.F., and Krishna, G. 1977. Phosgene: a metabolite of 43 chloroform. Biochem. Biophys. Res. Comm. 79:684-691. 44
45 Pohl, L.R., Martin, J.L., and George, J.W. 1980a. M echanism of metabolic activation of chloroform by 46

rat liver microsomes. Biochem. Pharmacol. 29:3271-3276. 47
48 Pohl, L.R., Martin, J.L., Taburet, A.M. and George, J.W. 1980b. Oxidative bioactivation of haloforms 49 into hepatotoxins. In: Microsomes, Drug Oxidati ons, and Chemical Carcinogenesis, Vol. II. 50 Coon, M.J., et al., Eds. Academic Press, New York. Pp. 881-884. 51PHOSGENE DRAFT REVISED 1: 10/2009 Page 53 of 73

1 Pohl, L.R., Branchflower, R.V., Highet, R. J., et al. 1981. The formation of diglutathionyl 2 dithiocarbonate as a metabolite of chloroform, br omotrichloromethane, and carbon tetrachloride. 3 Drug. Metab. Dispos. 9:334-338. 4
5 Polednak, A.P. and Hollis, D.R. 1985. Mortality and causes of death among workers exposed to 6 phosgene in 1943-1945. Toxicol. Ind. Health. 1:137-148. 7
8 Polednak, A.P. 1980. Mortality among men occupati onally exposed to phosgene in 1943-1945. Environ. 9

Res. 22:357-367. 10
11 Postel, S. and Swift, M. 1945. Evaluation of th e bleeding-transfusion treatment of phosgene poisoning. 12 In: Fasciculus on chemical warfare medicine: v. II, respiratory tract. Washington, DC: National 13 Research Council, Committee on Treatment of Gas Casualties; pp. 664-690. (Cited in U.S. 14 EPA, 1986) 15
16 Regan, R.A. 1985. Review of clinical experience in handling phosgene exposure cases. Toxicol. Ind. 17

Health. 1:69-71. 18
19 Reynolds, E.S. 1967. Liver parenchymal cell inju ry. IV. Pattern of incorporation of carbon and 20

chlorine from carbon tetrachloride into chemical c onstituents of liver in vivo. J. Pharmacol. 21 Exp. Ther. 155:126-127. 22
23 Rinehart, W.E. 1962. A study of the concentration x time (CT) relationship in sub-lethal exposures to 24 phosgene (dissertation). Pittsburgh, PA. Univer sity of Pittsburgh. Publication No. 62-6675. 25 University Microfilms, Inc. Ann Arbor, MI. 26
27 Rinehart, W.E. and Hatch, T. 1964. Concentr ation-time product (CT) as an expression of dose in 28 sublethal exposures to phosgene . AIHA Journal. 25:545-553. 29
30 Rothlin, E. 1941. Pathogenesis and treatment for phos gene intoxication. Schweiz. Med. Wochenschr. 31 71:1526-1535. (Cited in U.S. EPA, 1986) 32
33 Sandall, T.E. 1922. The later effects of gas pois oning. Lancet. 203: 857-859. (Cited in U.S. EPA, 34 1986) 35
36 Schultz, J. 1945. The prophylactic action of hexa methylenetetramine in phosgene poisoning. In: 37 Fasciculus on chemical warfare medicine: v. II, Respiratory tract. Washington, DC: National 38 Research Council, Committee on Treatment of Gas Casualties; pp. 691-712. 39
40 Sciuto, A.M. 1998. Assessment of early acute lung injury in rodents exposed to phosgene. Arch 41 Toxicology 72:283-288. 42
43
Sciuto, A.M., T.S. Moran, A. Narula and J.S. Forster. 2001. Disruption of ga s exchange in mice after exposure to 44 the chemical threat agent phosgene. Military Medicine 166, 9:809-814. 45
46 Selgrade, M.K., Starnes, D.M., Illing, J.W., Daniels, M.J., and Graham, J.A. 1989. Effects of phosgene 47 exposure on bacterial, viral, and neoplastic lung disease susceptability in mice. Inhalation 48

Toxicol. 1:243-259. 49
50PHOSGENE DRAFT REVISED 1: 10/2009 Page 54 of 73

Shah, H., Hartman, S.P., and Weinhouse, S. 1979. Formation of carbonyl chloride in carbon 1 tetrachloride metabolism by rat liver in vitro. Cancer Res. 39:3942-3947. 2
3 Shils, S.E. 1943. The therapeutic and prophylactic value of hexamethylenetetramine in phosgene 4 poisoning. MD (EA) Memorandum report Nr . 81 V. 19. (Cited in U.S. EPA, 1986) 5
6 Sipes, I.G., Krishna, G., and Gillette, J.R. 1977. Bioactivation of carbon tetrachloride, chloroform, and 7 bromotrichloromethane: role of cytochrome P-450. Life Sciences. 20: 1541-1548. 8
9 Slade, R., Highfill, J.W., and Hatch, G.E. 1989. E ffects of depletion of ascorbic acid or nonprotein 10 sulfhydryls on the acute inhalation toxicity of nitrogen dioxide, ozone, and phosgene. Inhalation 11

Toxicol. 1:261-271. 12
13 Stavrakis, P. 1971. The use of hexamethylenet etramine (HMT) in treatment of acute phosgene 14 poisoning. Ind. Med. 40:30-31. 15
16 TEMIS (Trauma Emergency Medical Information System). 1997. Phosgene. 17
18 ten Berge, W.F., Zwart, A. and Appleman, L.M. 1986. Concentration-time mortality response 19 relationship of irritant and systemically acting vapours and gases. J. Hazardous Materials 20

13:301-309. 21
22 Tobias, J.M. 1945. The pathological physiology of the lung after phosgene. In: Fasciculus on chemical 23 warfare medicine: v. II, respiratory tract. Washington, DC: National Research Council, 24 Committee on Treatment of Gas Casualties; pp. 331-391. (Cited in U.S. EPA, 1986) 25
26 Underhill, F.P. 1920. The lethal war gases. Physiol ogy and experimental treatment. New Haven Yale 27 University Press. 28
29 U.S. DHEW (U.S. Department of Health, Education, and Welfare). 1968. Eighth revision international 30 classification of diseases, adapted for use in th e United States. Public Health Services 31

Publication No. 1693:1. 32
33 U.S. EPA, 1985. Health Assessment Document for Chlo roform. Prepared by the Office of Health and 34 Environmental Assessment, Environmental Criteria and Assessment Office, Research Triangle 35 Park, NC, for the Office of Air Quality Planning and Standards. EPA 600/8-84-004F. 36
37

U.S. EPA. 1986. Health Assessment Document for Phosgene. Office of Health and Environmental 38

Assessment. EPA/600/8-86/022A. 39
40 Weston, R.E. and Karel, L. 1946. An application of the dosimetric method for biologically assaying 41

inhaled substances: The determination of the retain ed median lethal dose, percentage retention, 42 and respiratory response in dogs exposed to differe nt concentrations of phosgene. J. Pharmacol. 43 Exptl. Ther. 88:195. 44
45 Weston, R.E. and Karel, L. 1947. An adaptation of the dosimeteric method for use in smaller animals. 46 The retained median lethal dose and the respir atory response in normal, unanesthetized, Rhesus 47 monkeys (Macaca mulatta ) exposed to phosgene. J. Ind. Hyg. Toxicol. 29:29-33. 48
49PHOSGENE DRAFT REVISED 1: 10/2009 Page 55 of 73

Winternitz, M.C, Lambert, R.A., and Jackson, L. 1920. The pathology of phosgene poisoning. In: 1 Collected studies on the pathology of was gas poisoning. New Haven, CT: Yale Univ. Press; pp. 2

35-66. 3
4 Wirth, W. 1936. Uber die wirkung kleinster phosge nmengen. Arch. Exp. Pathol. Pharmacol. 181:198- 5

206. 6
7 Zwart, A., Arts, J.H.E., Klokman-Houweling, J.M ., and Schoen, E.D. 1990. Determination of 8 concentration-time-mortality relationships to replace LC50 values. Inhalation Toxicol. 2:105- 9

117. 10PHOSGENE DRAFT REVISED 1: 10/2009 Page 56 of 73

APPENDIX A: DERIVATION OF AEGL VALUES 1

2 AEGL-1 for Phosgene 3

4 Data were insufficient for derivation of AEGL-1 values for phosgene. 5

6PHOSGENE DRAFT REVISED 1: 10/2009 Page 57 of 73

Derivation of AEGL-2 for Phosgene 1

2 Key study: Pauluhn, 2006c 3

4 Toxicity endpoint: Increased PMNs in BAL fluid, dog (2.3 ppm for 30 min) 5

6 Scaling: C 1 x t = k 7 (2.3 ppm) 1 x 0.5 hr = 1.15 ppm

 hr 8

9

10 Uncertainty factors: 1 for interspecies variability 11 3 for intraspecies variability 12

13

10-min AEGL-2 C 1 x 0.167 hr = 1.15 ppm

 hr 14 C = 6.9 ppm 15 10-min AEGL-2 = 6.9/3 = 2.3 ppm 16

17 30-min AEGL-2 C = 2.3 ppm 18 30-min AEGL-2 = 2.3/3 = 0.77 ppm 19

20

1-hr AEGL-2 C 1 x 1 hr = 1.15 ppm

 hr 21 C = 1.15 ppm 22 1-hr AEGL-2 = 1.15 ppm/3 = 0.38 ppm 23

24

4-hr AEGL-2 C 1 x 4 hrs = 1.15 ppm

 hr 25 C = 0.29 ppm 26 4-hr AEGL-2 = 0.29 ppm/3 = 0.096 ppm 27

28

8-hr AEGL-2 C 1 x 8 hrs = 1.15 ppm

 hr 29 C = 0.14 ppm 30 8-hr AEGL-2 = 0.14 ppm/3 = 0.048 ppm 31PHOSGENE DRAFT REVISED 1: 10/2009 Page 58 of 73

Derivation of AEGL-3 for Phosgene 1

2 Key study: Pauluhn (2006a) 3

4 Toxicity endpoint: Estimated threshold for lethality in rats: BMCL 05 5 3.9 ppm for 1-hr 6

7 Scaling: C 1 x t = k 8 (3.9 ppm) 1 x 1 hr = 3.9 ppm

 hr 9

10 Uncertainty factors: 1 for interspecies variability 11 3 for intraspecies variability 12

13

10-min AEGL-3 C 1 x 0.167 hr = 3.9 ppm

 hr 14 C = 23.35 ppm 15 10-min AEGL-3 = 23.35/3 = 7.8 ppm 16

17

30-min AEGL-3 C 1 x 0.5 hr = 3.9 ppm

 hr 18 C = 7.8 ppm 19 10-min AEGL-3 = 7.8/3 = 2.6 ppm 20

21 1-hr AEGL-3 C = 3.9 ppm 22 1-hr AEGL-3 = 3.9 ppm/3 = 1.3 ppm 23

24

4-hr AEGL-3 C 1 x 4 hrs = 3.9 ppm

 hr 25 C = 0.975 ppm 26 4-hr AEGL-3 = 0.975 ppm/3 = 0.33 ppm 27

28

8-hr AEGL-3 C 1 x 8 hrs = 3.9 ppm

 hr 29 C = 0.488 ppm 30 8-hr AEGL-3 = 0.488 ppm/3 = 0.16 ppm 31PHOSGENE DRAFT REVISED 1: 10/2009 Page 59 of 73



### APPENDIX B: DERIVATION SUMMARY FOR PHOSGENE AEGLS 1

2
ACUTE EXPOSURE GUIDELINE LEVELS FOR PHOSGENE 3
DERIVATION SUMMARY 4

5

AEGL-1 VALUES FOR PHOSGENE

10-min 30-min 1-hr 4-hr 8-hr

NR NR NR NR NR
Key Reference: NA Test Species/Strain/Number : NA Exposure Route/Concentrations/Durations: NA

Effects : NA Endpoint/Concentration/Rationale : NA Uncertainty Factors/Rationale : NA Modifying Factor: NA Animal to Human Dosimetric Adjustment : NA Time Scaling: NA Confidence and Support for AEGL values : Data were insufficient for derivation of AEGL-1 values for phosgene. Odor cannot be used as a warning for poten tial exposure. The odor threshold is reported to be between 0.5 to 1.5 ppm, a value above or approachi ng AEGL-2 and AEGL-3 values, and tolerance to the pleasant odor of phosgene occurs rapidly. Furtherm ore, following odor detection and minor irritation, serious effects may occur after a clinical latency period of  24 hours.PHOSGENE DRAFT REVISED 1: 10/2009 Page 60 of 73

1

AEGL-2 VALUES FOR PHOSGENE

10-min 30-min 1-hr 4-hr 8-hr 2.3 ppm (9.5 mg/m 3 ) 0.77 ppm (3.2 mg/m 3 ) 0.38 ppm (1.6 mg/m 3 ) 0.096 ppm (0.39 mg/m 3 ) 0.048 ppm (0.19 mg/m 3 )
Key Reference: Pauluhn, J. 2006c. Acute head-only exposure of dogs to phosgene. Part III. Comparison of indicators of lung injury in dogs a nd rats. Inhalation Toxicology 18:609-621. Test Species/Strain/Number: Dog/ Beagle/4-5 males and/or females/concentration Exposure Route/Concentrations/Durations : Dogs/Inhalation: 30 minute exposures to 0, 2.3, 4.1, or 8.8 ppm

Effects : 2.3 ppm: nasal discharge, salivation lacrimation 4.1 ppm: nasal discharge, salivation lacrimation, increased BAL PMNs 8.8 ppm: labored breathing, rales, increased BAL PM Ns, increased lung weight, pulmonary pathology edema Endpoint/Concentration/Rationale: NOAEL for increased PMNs in BAL fluid / BAL fluid changes are a sensitive marker of phosgene-induced noncardiogenic pulmonary high-permeability edema following acute inhalation exposure Uncertainty Factors/Rationale : Total uncertainty factor : 3 Interspecies : 1 An increase BAL fluid protein is a sensitive marker of phosgene-induced noncardiogenic pulmonary high-permeability edema following acute inhalation exposure (Pauluhn et al., 2007). In rats, c x t products of between 48 ppm·min and 60 ppm·min induced increased protein in BAL fluid , and no increase was noted from 24-30 ppm·min. In mice and hamste rs, a c x t product of 48 ppm·min induced an increase of protein in BAL fluid, and no increase was noted at 24 ppm·min. However, in dogs, a c x t product of 129 ppm·min was necessary to cause an increase in prot ein in BAL fluid, and no increase was observed at 63 ppm·min. Thus, the CT product required to induce an incr ease in protein in BAL fluid in dogs is approximately two-fold greater than in rodents, and the NOAEL for increased BAL protein in dogs (63 ppm·min) is higher than the LOAEL values in rodents (48-60 ppm·min). Additiona lly, with regard physiology of the respiratory tract and acinar structure of the lung, dogs are more simila r to humans than rodents (Pauluhn, 2006a, 2006b, 2006c; Pauluhn et al., 2007). Collectively, these data suggest that an interspecies uncertainty factor of no more than 1 is justified when extrapolating from laboratory animals to humans.

Intraspecies : 3 - considered sufficient due to the steep concentration-response curve (death in 2/10 rats exposed to 52.3 ppm and 6/10 exposed to 61.9 ppm fo r 10 min; 4/10 exposed to 13.4 ppm and 10/10 exposed to 16.7 ppm for 30-min; 4/10 exposed to 7.4 ppm a nd 10/10 exposed to 11.8 ppm for 1-hr; Pauluhn, 2006a) which implies limited intra-individual variability. Also, the mechanism of phosgene toxicity (binding to macromolecules and irritation) is not expect ed to vary greatly between individuals. Modifying Factor: Not applicable Animal to Human Dosimetric Adjustment: Insufficient data Time Scaling: C n x t = k where n = 1. Haber = s Law c x t = k; n=1 has been shown to be valid for phosgene within certain limits and was used for scaling of the AEGL values for phosgene. Data adequacy: The database is rich. The calculated AEGL -2 values are supported by repeated-exposure rat studies where No significant treatment-related effects were noted in rats exposed to 0.125 ppm phosgene 4 hours/day, 5 days/week for 17 weeks (Franch and Hatch, 1986).PHOSGENE DRAFT REVISED 1: 10/2009 Page 61 of 73

1

AEGL-3 VALUES FOR PHOSGENE

10-min 30-min 1-hr 4-hrs 8-hrs 7.8 ppm (32 mg/m 3 ) 2.6 ppm (11 mg/m 3 ) 1.3 ppm (5.3 mg/m 3 ) 0.33 ppm (1.4 mg/m 3 ) 0.16 ppm (0.66 mg/m 3 )

Reference: Pauluhn, J. 2006a. Acute nose-only exposure of ra ts to phosgene. Part I. Concentration x time dependence of LC 50 s, non-lethal-threshold concentrations and analysis of breathing patterns. Inhalation Toxicology 18:423-435. Test Species/Strain/Sex/Number: Wistar rats/ 5 males and 5 females/ concentration Exposure Route/Concentrations/Durations: Rats/Inhalation: 41.1, 44.8, 52. 3, 61.9 ppm for 10-min; 12.6, 13.4, 16.7, 21.4 ppm for 30-min; 0, 7.4, 9.7, 11.8 ppm for 1-hr; 2.2 and 2.7 ppm for 4-hr.

Effects : Mortality LC 50 BMCL 05 BMC 01 Concentration (ppm) Exposure duration

(min) M F

41.1 10 2/5 1/5 44.8 10 0/5 0/5 52.3 10 1/5 1/5 61.9 10 3/5 3/5 62.5 ppm 24.3 ppm 32.6 ppm

12.6 30 3/5 1/5 13.4 30 3/5 1/5 16.7 30 5/5 5/5 21.4 30 5/5 4/5 13.5 ppm 5.0 ppm 7.4 ppm

0 60 0/5 0/5 7.4 60 2/5 2/5 9.7 60 5/5 4/5 11.8 60 5/5 5/5 7.7 ppm 3.9 ppm 5.3 ppm

2.2 240 5/5 1/5 2.7 240 5/5 4/5 2.1 ppm - -

Endpoint /Concentration/Rationale: Estimated lethality threshold (BMCL 05 ) in rats/ 3.9 ppm for 1-hr Uncertainty Factors/Rationale: Total uncertainty factor : 3 Interspecies : 1- An increase BAL fluid protein is a sensitive marker of phosgene-induced noncardiogenic pulmonary high-permeability edema follo wing acute inhalation exposure (Pauluhn et al., 2007). In rats, c x t products of between 48 ppm·min and 60 ppm·min induced increased protein in BAL fluid , and no increase was noted from 24-30 ppm·min. In mice and hamsters, a c x t product of 48 ppm·min induced an increase of protein in BAL fluid, and no in crease was noted at 24 ppm·min. However, in dogs, a c x t product of 129 ppm·min was necessary to cause an in crease in protein in BAL fluid, and no increase was observed at 63 ppm·min. Thus, the CT product required to induce an increase in protein in BAL fluid in dogs is approximately two-fold greater than in rodents, and the NOAEL for increased BAL protein in dogs (63 ppm·min) is higher than the LOAEL values in rodents (48-60 ppm·min). Additionally, with regard physiology of the respiratory tract and acinar structure of the lung, dogs are more similar to humans than rodents (Pauluhn, 2006a, 2006b, 2006c; Pauluhn et al., 2007). Collectively, these data suggest that an interspecies uncertainty factor of no more than 1 is justified when extrapolating from laboratory animals to humans.

Intraspecies : 3 - considered sufficient due to the steep concentration-response curve (death in 2/10 rats exposed to 52.3 ppm and 6/10 exposed to 61.9 ppm for 10 min; 4/10 exposed to 13.4 ppm and 10/10 exposed to 16.7 ppm for 30-min; 4/10 exposed to 7.4 ppm and 10/10 exposed to 11.8 ppm for 1-hr; Pauluhn, 2006a) which implies limited intra-individual variability. Also, the mechanism of phosgene toxicity (binding to macromolecules a nd irritation) is not expected to vary greatly
between individuals. Modifying Factor: Not applicable Animal to Human Dosimetric Adjustment: Insufficient data Time Scaling : C n x t = k where n = 1. Haber = s Law c x t = k; n=1 has been shown to be valid for phosgene within certain limits and was used for scaling of the AEGL values for phosgene.PHOSGENE DRAFT REVISED 1: 10/2009 Page 62 of 73

Data Adequacy: The AEGL-3 values are based on a well-conducte d study in rats and the database is rich. AEGL-3 values are considered protec tive. No deaths were noted in rats exposed to phosgene 6 hrs/day at concentrations of 0.1 ppm (5 days/week), 0.2 ppm (5 days/week), 0.5 ppm (2 days/week) or 1.0 ppm (1 day/week) for 4 or 12 weeks (Kodavanti et al.,1997). Also, no deaths were noted in approximately 200 workers exposed to phosgene concentrations ranging from 50 to 300 ppm·min (Kaerkes, 1992), and calculated AEGL-3 values are approximately 79 ppm·min.

1PHOSGENE DRAFT REVISED 1: 10/2009 Page 63 of 73

APPENDIX C: CATEGORY PLOT FOR PHOSGENE 1 2
3

0 0 1 10 100ppm

0 60 120 180 240 300 360 420 480
Minutes Human - No Effect

Human - Discomfort

Human - Disabling

Animal - No Effect

Animal - Discomfort

Animal - Disabling

Animal - Some Lethality

Animal - Lethal

AEGL Chemical Toxicity - TSD All Data Phosgene

AEGL-3

AEGL-2

4 5PHOSGENE DRAFT REVISED 1: 10/2009 Page 64 of 73

1 Phosgene N

For Category 0 = No effect, 1 = Discomfort, 2 = Disabling, PL = Partially Lethal,
3 = Lethal

Source Species Sex # Exposures ppm Minutes Category Comments

NAC/AEGL-1 NR 10 AEGL

NAC/AEGL-1 NR 30 AEGL

NAC/AEGL-1 NR 60 AEGL

NAC/AEGL-1 NR 240 AEGL

NAC/AEGL-1 NR 480 AEGL

NAC/AEGL-2 2.3 10 AEGL

NAC/AEGL-2 0.77 30 AEGL

NAC/AEGL-2 0.38 60 AEGL

NAC/AEGL-2 0.096 240 AEGL

NAC/AEGL-2 0.048 480 AEGL

NAC/AEGL-3 7.8 10 AEGL

NAC/AEGL-3 2.6 30 AEGL

NAC/AEGL-3 1.3 60 AEGL

NAC/AEGL-3 0.33 240 AEGL

NAC/AEGL-3 0.16 480 AEGL mouse 1 77 10 pl LC50 (Zwart, 1990) male mouse 1 61 10 pl LC50 (Zwart, 1990) female mouse 1 18 30 pl LC50 (Zwart, 1990) male mouse 1 11 30 pl LC50 (Zwart, 1990) female mouse 1 9 10 pl LC50 (Zwart, 1990) male mouse 1 5 15 pl LC50 (Zwart, 1990) female

rat 1 0.29 30 1 transient decreased minute
volume (Pauluhn, 2006a) rat 1 1 240 pl increased lung weight, BAL protein (Pauluhn, 2006a) rat 1 41.1 10 pl mortality 3/10; lung edema, pulmonary hemorrhage, foamy trachael exudate (Pauluhn, 2006a) rat 1 44.8 10 2 mortality 0/10; lung edema, pulmonary hemorrhage, foamy trachael exudate (Pauluhn, 2006a)PHOSGENE DRAFT REVISED 1: 10/2009 Page 65 of 73

rat 1 52.3 10 pl mortality 2/10; lung edema, pulmonary hemorrhage, foamy trachael exudate (Pauluhn, 2006a) rat 1 61.9 10 pl mortality 6/10; lung edema, pulmonary hemorrhage, foamy trachael exudate (Pauluhn, 2006a) rat 1 12.6 30 pl mortality 4/10; lung edema, pulmonary hemorrhage, foamy trachael exudate (Pauluhn, 2006a) rat 1 13.4 30 pl mortality 4/10; lung edema, pulmonary hemorrhage, foamy trachael exudate (Pauluhn, 2006a) rat 1 16.7 30 3 mortality 10/10; lung edema, pulmonary hemorrhage, foamy trachael exudate (Pauluhn, 2006a) rat 1 21.4 30 pl mortality 9/10; lung edema, pulmonary hemorrhage, foamy trachael exudate (Pauluhn, 2006a) rat 1 7.4 60 pl mortality 4/10; lung edema, pulmonary hemorrhage, foamy trachael exudate (Pauluhn, 2006a) rat 1 9.7 60 pl mortality 9/10; lung edema, pulmonary hemorrhage, foamy trachael exudate (Pauluhn, 2006a) rat 1 11.8 60 3 mortality 10/10; lung edema, pulmonary hemorrhage, foamy trachael exudate (Pauluhn, 2006a) rat 1 2.2 240 pl mortality 6/10; lung edema, pulmonary hemorrhage, foamy trachael exudate (Pauluhn, 2006a) rat 1 2.7 240 pl mortality 9/10; lung edema, pulmonary hemorrhage, foamy trachael exudate (Pauluhn, 2006a) rat 1 80 10 pl LC50 (Zwart, 1990) rat 1 20 30 pl LC50 (Zwart, 1990) rat 1 12 60 pl LC50 (Zwart, 1990) rat 1 4 75 pl LC50 (Rinehart & Hatch, 1964)) rat 1 4 125 3 LC100 (Rinehart & Hatch, 1964) mouse 1 8 20 2 Increased lung weight, acidosis (Sciuto, 2001) mouse 1 22 20 2 Increased protein in BAL fluid (Sciuto, 1998) rat 1 22 20 2 Increased protein in BAL fluid (Sciuto, 1998) gp 1 22 20 2 Increased protein in BAL fluidPHOSGENE DRAFT REVISED 1: 10/2009 Page 66 of 73

(Sciuto, 1998) mouse 1 0.2 240 2 Increased protein in BAL fluid (Hatch, 1986) mouse 1 0.15 240 2 Increased phenobarbital-induced sleep time (Illing, 1988) rat 1 0.2 30 0 no effect reported (Pauluhn 2006b) rat 1 0.5 30 0 no effect reported (Pauluhn 2006b) rat 1 1 30 0 no effect reported (Pauluhn 2006b)

rat 1 2 30 2 labored breathing, tachypnea, decreased BW, increased BAL protein (Pauluhn, 2006b) rat 1 4 30 2 lung pathology, labored breathing, tachypnea, decreased BW, increased BAL protein (Pauluhn, 2006b) rat 1 2 90 2 chemical pneumonia (Gross, 1965) rat 1 0.05 240 0 no effect reported (Pauluhn 2006b) rat 1 0.1 240 0 no effect reported (Pauluhn 2006b) rat 1 0.2 240 2 labored breathing, tachypnea, decreased BW, increased BAL protein (Pauluhn, 2006b) rat 1 0.4 240 2 labored breathing, tachypnea, decreased BW, increased BAL protein (Pauluhn, 2006b) rat 1 1 240 2 lung pathology, labored breathing, tachypnea, decreased BW, increased BAL protein (Pauluhn, 2006b) rat 1 1 240 2 decreased BW, increased lung weight (Erlich, 1989) gp 1 0.25 240 2 increased protein in BAL fluid (Slade, 1989) gp 1 0.5 240 2 increased protein in BAL fluid (Slade, 1989) rat 1 0.125 240 0 no effect reported (Currie, 1987a) rat 1 0.25 240 2 increased protein BAL fluid (Currie, 1987a) rat 1 0.5 240 2 increased protein BAL fluid, increased lung weight (Currie, 1987a) rat 1 1 240 2 increased protein BAL fluid, increased lung weight (Currie, 1987a)PHOSGENE DRAFT REVISED 1: 10/2009 Page 67 of 73

rat 1 0.1 240 0 no effect reported (Hatch, 1986) rat 1 0.2 240 2 increased lBAL protein (Hatch, 1986) mouse 1 0.1 240 0 no effect reported (Hatch, 1986) mouse 1 0.2 240 2 increased BAL protein (Hatch, 1986) hamster 1 0.1 240 0 no effect reported (Hatch, 1986)

hamster 1 0.2 240 2 increased BAL protein (Hatch, 1986) rabbit 1 0.2 240 0 no effect reported (Hatch, 1986) rabbit 1 0.5 240 2 increased BAL protein (Hatch, 1986) gp 1 0.2 240 0 no effect reported (Hatch, 1986) gp 1 0.5 240 2 increased BAL protein (Hatch, 1986) dog 1 2.3 30 1 nasal discharge, salivation,
lacrimation (Pauluhn, 2006c)

dog 1 4.1 30 1 nasal discharge, salivation, lacrimation; increased BAL PMNs (Pauluhn, 2006c)

dog 1 8.8 30 2 labored breathing, rales, increased lung weight, pulmonary pathology and
edema (Pauluhn, 2006c)

1PHOSGENE DRAFT REVISED 1: 10/2009 Page 68 of 73

BMDS MODEL RUN Phosgene 30 min 1

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 2

3 The form of the probability function is: 4

5 P[response] = Background 6 + (1-Background) * CumNorm(Intercept+Slope*Log(Dose)), 7

8 where CumNorm(.) is the cumulative normal distribution function 9

10

11 Dependent variable = COLUMN3 12 Independent variable = COLUMN1 13 Slope parameter is not restricted 14

15
Total number of observations = 5 16 Total number of records with missing values = 0 17
Maximum number of iterations = 250 18 Relative Function Convergence has been set to: 1e-008 19 Parameter Convergence has been set to: 1e-008 20

21

22

23 User has chosen the log transformed model 24

25

26 Default Initial (and Specified) Parameter Values 27 background = 0 28 intercept = -8.93912 29 slope = 3.47228 30

31

32 Asymptotic Correlation Matrix of Parameter Estimates 33

34 ( *** The model parameter(s) -background 35 have been estimated at a boundary point, or have been specified by the user, 36 and do not appear in the correlation matrix ) 37

38 intercept slope 39

40 intercept 1 -1 41

42 slope -1 1 43

44

45

46PHOSGENE DRAFT REVISED 1: 10/2009 Page 69 of 73

Parameter Estimates 1

2
Variable Estimate Std. Err. 3 background 0 NA 4 intercept -10.2513 3.55375 5 slope 3.95309 1.32526 6

7 NA - Indicates that this parameter has hit a bound 8 implied by some inequality constraint and thus 9
has no standard error. 10

11 Analysis of Deviance Table 12

13 Model Log(likelihood) Deviance Test DF P-value 14
Full model -16.7111 15
Fitted model -19.5263 5.63053 3 0.131 16
Reduced model -34.4972 35.5722 4 <.0001 17

18

AIC: 43.0527 19
Goodness of Fit 20

21
Scaled 22 Dose Est._Prob. Expected Observed Size Residual 23

------------------------------------------------------------------------ 24

0.0000 0.0000 0.000 0 10 0 25

12.6000 0.4070 4.070 4 10 -0.04492 26

13.4000 0.5032 5.032 4 10 -0.6527 27

16.7000 0.8101 8.101 10 10 1.531 28

21.4000 0.9685 9.685 9 10 -1.239 29

30 Chi-square = 4.31 DF = 3 P-value = 0.2302 31

32

33 Benchmark Dose Computation 34

35 Specified effect = 0.05 36

37 Risk Type = Extra risk 38

39
Confidence level = 0.95 40

41

BMD = 8.82098 42

43

BMDL = 5.01841 44PHOSGENE DRAFT REVISED 1: 10/2009 Page 70 of 73

0 0.2 0.4 0.6 0.8

1

0 5 10 15 20Fraction Affected

dose Probit Model with 0.95 Confidence Level

11:01 08/13 2009 BMDL BMD Probit

1PHOSGENE DRAFT REVISED 1: 10/2009 Page 71 of 73

BMDS MODEL RUN Phosgene 1 hr 1

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 2

3 The form of the probability function is: 4

5 P[response] = Background 6 + (1-Background) * CumNorm(Intercept+Slope*Log(Dose)), 7

8 where CumNorm(.) is the cumulative normal distribution function 9

10

11 Dependent variable = COLUMN3 12 Independent variable = COLUMN1 13 Slope parameter is not restricted 14

15
Total number of observations = 4 16 Total number of records with missing values = 0 17
Maximum number of iterations = 250 18 Relative Function Convergence has been set to: 1e-008 19 Parameter Convergence has been set to: 1e-008 20

21

22

23 User has chosen the log transformed model 24

25

26 Default Initial (and Specified) Parameter Values 27 background = 0 28 intercept = -8.66339 29 slope = 4.25842 30

31

32 Asymptotic Correlation Matrix of Parameter Estimates 33

34 ( *** The model parameter(s) -background 35 have been estimated at a boundary point, or have been specified by the user, 36 and do not appear in the correlation matrix ) 37

38 intercept slope 39

40 intercept 1 -1 41

42 slope -1 1 43

44

45

46PHOSGENE DRAFT REVISED 1: 10/2009 Page 72 of 73

Parameter Estimates 1

2
Variable Estimate Std. Err. 3 background 0 NA 4 intercept -12.3592 4.62176 5 slope 6.03934 2.18595 6

7 NA - Indicates that this parameter has hit a bound 8 implied by some inequality constraint and thus 9
has no standard error. 10

11

12

13 Analysis of Deviance Table 14

15 Model Log(likelihood) Deviance Test DF P-value 16
Full model -9.98095 17
Fitted model -10.0476 0.133401 2 0.9355 18
Reduced model -27.2742 34.5865 3 <.0001 19

20

AIC: 24.0953 21

22

23
Goodness of Fit 24

25
Scaled 26 Dose Est._Prob. Expected Observed Size Residual 27

------------------------------------------------------------------------ 28

0.0000 0.0000 0.000 0 10 0 29

7.4000 0.3930 3.930 4 10 0.04559 30

9.7000 0.9135 9.135 9 10 -0.1524 31

11.8000 0.9946 9.946 10 10 0.2339 32

33 Chi-square = 0.08 DF = 2 P-value = 0.9608 34

35

36 Benchmark Dose Computation 37 Specified effect = 0.05 38 Risk Type = Extra risk 39

40
Confidence level = 0.95 41

42

BMD = 5.89496 43

44

BMDL = 3.90643 45PHOSGENE DRAFT REVISED 1: 10/2009 Page 73 of 73

0 0.2 0.4 0.6 0.8

1

0 2 4 6 8 10 12Fraction Affected

dose Probit Model with 0.95 Confidence Level

11:09 08/13 2009 BMDL BMD Probit

1 2 3